Routers, It's function and Types

Router

A router is a computer networking device, commonly specialized hardware that forwards data packets between computer networks. It is layer three (Network Layer) device. It forwards the packet on the basis of Routed Protocols such as IP, IPv6, and IPX etc.
This device is generally used to communicate between two or more than two different segment, different network or LAN. It means If you have two identical LAN, established in two different location such as New York and Arizona. And you want to make connection between them; Router can solve your problem.
This creates an overlay internetwork, as a router is connected to two or more data lines from different networks. When a data packet comes in one of the lines, the router reads the address information in the packet to determine its ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey.
A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it reaches its destination node.

Functions
Router has generally three main functions.

PACKET FORWARDING:

Router maintains a routing table for all possible networks those can be reached. In the routing table, a router maintains, subnet, Gateway, forwarding interface, timing etc of the destination network. If multiple paths exist to reach the destination network, only best path is maintained in the routing table. Once any packet is received, it checks the destination IP network in the routing table. If destination network is available in routing table, It forwards the packet otherwise it drops.

PACKET SWITCHING:

To move packets from one interface to another to get a packet to its destination.

PACKET FILTERING:

Packet filtering is such like firewall. By which you can define which network can be entered and which network can be dropped. In easy word, It filters the packet on the basis of IP address, subnet, port no and protocols.

Types of Routers
There are several types of routers that you will want to understand. You need to know the difference so that you can set up your network or at least so that you can understand what the local computer guy tells you to do.

Broadband Routers

Broadband routers can be used to do several different types of things. They can be used to connect two different computers or to connect two computers to the Internet. They can also be used to create a phone connection. If you are using Voice over IP (VoIP) technology, then you will need a broadband router to connect your Internet to your phone. These are often a special type of modem that will have both Ethernet and phone jacks. Although this may seem a little confusing, simply follow the instructions that your VoIP provider sends with your broadband router - usually you must purchase the router from the company in order to obtain the service.

Wireless Routers

Wireless routers connect to your modem and create a wireless signal in your home or office. So, any computer within range can connect to your wireless router and use your broadband Internet for free. The only way to keep anyone from connecting to your system is to secure your router.

Android: The Heart of Smartphones

Android

In the today's world, Android is not a word which needa introduction. It is now over five years old. Android powers hundreds of millions of mobile devices in more than 190 countries around the world. It is the largest installed operating system and growing fast everyday. As the number of users increasing day by day facilities are also increasing. Millions of new users are adopting Android as their mobile platform and start looking for apps, games and other digital content.

Operating systems have developed a lot in last fifteen years. Starting from the Black&White phones to recent smartphones or mini computers, mobile OS has come far away.

Android is a powerful operating system supporting large number of applications. Android gives you a world class platform for creating apps and games for Android users everywhere, as well as an open market place for distributing them instantly. This open market is an online software store. It was developed by Google. It allows Android users to select and download applications developed by the third party developers & use them. Android applications are written in Java programming language.

Open Android market like Google play store or the Amazon Appstore allows users to browse, download and update applications published by Google or third party developers. The client application filters the list of available applications down to those compatible with user's device & developer may restrict their applications to particular carriers or countries for business reasons.

  Android applications are composed of one or more application components ( activities, services, content providers, & broadcast receivers).
   Each component performs a different role in the overall application behavior & each one be activated individually.

Android Updates
Google is constantly working on new versions of android software.
- Android 1.5 Cupcake
- Android 1.6 Donut
- Android 2.1 Eclair
- Android 2.3 Gingerbread
- Android 3.2 Honeycomb
- Android 4.0 Icecream Sandwich
- Android 4.1 Jelly Bean
- Android 4.2 Jelly Bean
- Android 4.3 Jelly Bean
- Android 4.4 Kitkat

Google play puts you in control of how you sell your products. You can publish whenever you want, as often you want & to the customer you want. You can distribute broadly to all markets & devices or focus on specific segment, devices or ranges of hardware capabilities.

Hacking

Welcome to The Engineering Articles
What is Hacking?
Hacking is the practice of modifying the features of a system, in order to accomplish a goal outside of the creator's original purpose. The person who is consistently engaging in hacking activities, and has accepted hacking as a lifestyle and philosophy of their choice, is called a hacker .
Or
Computer Hacking is a practice of peeping into the extreme technical details of any computer application, program, or the whole system in order to extend its capabilities or alter its functionalities. People who rightly follow this practice of hacking are termed as ‘hackers’ . A hacker’s vision towards solving any technical problem is undoubtedly beyond the perception of any normal computer expert.

This practice can either be ethical or unethical.
The activity where one breaks into the system but do not violate its security and credentials is called Ethical Hacking . Ethical hackers aim to bring into the administrator’s notice, vulnerabilities and voids in the system thereby, improvising the robustness and security. They are purely tech- geeks with immaculate programming skills and hands-on knowledge on both computer hardware and software. On the other hand, there are people who can though break into systems, get access to secured accounts but their actions are usually unauthorized while they make a backdoor entry into your system. These people (often misinterpreted as hackers) are called as ‘crackers’ . They try and crack passwords, security codes, etc using various hacking softwares which are already available. Such softwares are meant to break the code using millions of trials programmed into it by other hackers.
While hacking can prove really useful when companies hire hackers to keep a check on the security of their network and transactions, it may be equally harmful even to an individual operating his/her personal computer sitting at home.

Footprinting

Footprinting is an analogous step which hackers take before gaining access into any network. The systematic footprinting of an organization enables attackers to create a complete profile of an organization’s security posture like system architecture, network blocks and IP addresses exposed on the Internet .
Hackers gain reconnaissance of the target following a sequence of steps as:

1. Open Source Footprinting- The first step a hacker takes is to visit the website of a potential target. He then looks for contact information of the administrators which may help in guessing the password or in Social Engineering.

2. Network Enumeration- This is the next step in gaining information where the hacker tries to identify the domain names and the network blocks of the target network.

3. Scanning- Once the network block is known, the next step is to spy for active IP addresses on the target network. The Internet Control Message Protocol (ICMP) is a good alternative for identifying active IP addresses.

4. Stack Fingerprinting- Once the hosts and port have been mapped by scanning the target network, the final footprinting step can be performed. This step is called stack fingerprinting. This is the process of determining the operating system and different version of services running on target hosts.

Computer hacking is the most popular form of hacking nowadays, especially in the field of computer security, but hacking exists in many other forms, such as phone hacking, brain hacking, etc. and it's not limited to either of them. Due to the mass attention given to blackhat hackers from the media, the whole hacking term is often mistaken for any security related cyber crime. This damages the reputation of all hackers, and is very cruel and unfair to the law abiding ones of them, from who the term itself originated. 

Search Engine Optimization (SEO)

Welcome to The Engineering Articles
Today we gonna take a look at Search Engine Optimization.

What is SEO?
SEO is the process of improving the organic ranking of a website with leading search engines. Professional SEO firms help to improve search engine rankings for their clients by modifying their websites to better reflect what search engines are looking for.
Or
Search engine optimization ( SEO ) is the process of affecting the visibility of a website or a web page in a search engine 's "natural" or un-paid ("organic ") search results.  All major search engines such as Google , Yahoo and Bing have such results, where web pages and other content such as videos or local listings are shown and ranked based on what the search engine considers most relevant to users.

As an Internet marketing strategy, SEO considers how search engines work, what people search for, the actual search terms or keywords typed into search engines and which search engines are preferred by their targeted audience. Optimizing a website may involve editing its content, HTML and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO
tactic.

SEO techniques can be of different types

 White hat SEO

In search engine optimization ( SEO ) terminology, white hat SEO refers to the usage of optimization strategies, techniques and tactics that focus on a human audience opposed to search engines and completely follows search engine rules and policies.

For example, a website that is optimized for search engines, yet focuses on relevancy and organic ranking is considered to be optimized using White Hat SEO practices. Some examples of White Hat SEO techniques include using keywords and keyword analysis, backlinking , link building to improve link popularity, and writing content for human readers. White Hat SEO is more frequently used by those who intend to make a long-term investment on their website. Also called Ethical SEO .

Black Hat SEO

In search engine optimization ( SEO ) terminology, black hat SEO refers to the use of aggressive SEO strategies, techniques and tactics that focus only on search engines and not a human audience, and usually does not obey search engines guidelines.
Some examples of black hat SEO techniques include keyword stuffing, invisible text, doorway pages, adding unrelated keywords to the page content or page swapping (changing the webpage entirely after it has been ranked by search engines).
Black Hat SEO Usage
Black hat SEO is more frequently used by those who are looking for a quick financial return on their Web site, rather than a long-term investment on their Web site. Black hat SEO can possibly result in your Web site being banned from a search engine , however since the focus is usually on quick high return business models, most experts who use Black Hat SEO tactics consider being banned from search engines a somewhat irrelevant risk. Black hat SEO may also be referred to as unethical SEO or spamdexing , as spamdexing is a frequently used black hat SEO practice.

E-Commerce

Welcome back to The Engineering Articles
Today we look at the topic E-Commerce
What is E-Commerce?
Electronic commerce or ecommerce is a term for any type of business, or commercial transaction that involves the transfer of information across the Internet.
Or
A type of business model, or segment of a larger business model, that enables a firm or individual to conduct business over an electronic network, typically the internet.

Electronic commerce operates in all four of the major market segments: business to business, business to consumer, consumer to consumer and consumer to business. It can be thought of as a more advanced form of mail-order purchasing through a catalog. Almost any product or service can be offered via ecommerce, from books and music to financial services and plane tickets.

Ecommerce has allowed firms to establish a market presence, or to enhance an existing market position, by providing a cheaper and more efficient distribution chain for their products or services. Ecommerce allows consumers to electronically exchange goods and services with no barriers of time or distance. Electronic commerce has expanded rapidly over the past five years and is predicted to continue at this rate, or even accelerate. In the near future the boundaries between "conventional" and "electronic" commerce will become increasingly blurred as more and more businesses move sections of their operations onto the Internet. Ecommerce is often faster, cheaper and more convenient than the traditional methods of bartering goods and services. Electronic commerce is generally considered to be the sales aspect of e-business. It also consists of the exchange of data to facilitate the financing and payment aspects of business transactions. This is an effective and efficient way of communicating within an organization and one of the most effective and useful ways of conducting business. It is a market entry strategy where the company may or may not have a physical presence.

Advantages and Disadvantages

When you purchase a good or service online, you are participating in ecommerce.
Some advantages of ecommerce for consumers are:
- Convenience. Ecommerce can take place 24 hours a day, seven days a week.
- Selection. Many stores offer a wider array of products online than they do in their brick-and-mortar counterparts. And stores that exist only online may offer consumers a selection of goods that they otherwise could not access.
But ecommerce also has its disadvantages for consumers:
- Limited customer service. If you want to buy a computer and you’re shopping online, there is no employee you can talk to about which computer would best meet your needs.
- No instant gratification. When you buy something online, you have to wait for it to be shipped to your home or office.
- No ability to touch and see a product. Online images don’t always tell the whole story about an item. Ecommerce transactions can be dissatisfying when the product the consumer receives is different than expected.

How E-Conmerce works?

Shopping cart software is an operating system used to allow consumers to purchase goods and or services, track customers, and tie together all aspects of ecommerce into one cohesive whole. While there are many types of software that you can use, customizable, turnkey solutions are proven to be a cost effective method to build, edit and maintain an online store. How do online shopping carts differ from those found in a grocery store? The image is one of an invisible shopping cart. You enter an online store, see a product that fulfills your demand and you place it into your virtual shopping basket. When you are through browsing, you click checkout and complete the transaction by providing payment information.
To start an online business it is best to find a niche product that consumers have difficulty finding in malls or department stores. Also take shipping into consideration. Then you need an ecommerce enabled website. This can either be a new site developed from scratch, or an existing site to which you can add ecommerce shopping cart capabilities. The next step, you need a means of accepting online payments. This usually entails obtaining a merchant account and accepting credit cards through an online payment gateway. Lastly, you need a marketing strategy for driving targeted traffic to your site and a means of enticing repeat customers. If you are new to ecommerce keep things simple- know your limitations.
Ecommerce can be a very rewarding venture, but you cannot make money overnight. It is important to do a lot of research, ask questions, work hard and make on business decisions on facts learned from researching ecommerce.

Web Hosting and It's Types

Welcome Back to The Engineering Articles

What is Web hosting??

A web hosting service is a type of Internet hosting service that allows individuals and organizations to make their website accessible via the World Wide Web . Web hosts are companies that provide space on a server owned or leased for use by clients, as well as providing Internet connectivity, typically in a data center. Web hosts can also provide data center space and connectivity to the Internet for other servers located in their data center, called colocation. The scope of web hosting services varies greatly. The most basic is web page and small-scale file hosting, where files can be uploaded via File Transfer Protocol (FTP) or a Web interface. The files are usually delivered to the Web "as is" or with minimal processing.

Many Internet service providers (ISPs) offer this service free to subscribers. Individuals and organizations may also obtain Web page hosting from alternative service providers. Personal web site hosting is typically free, advertisement-sponsored, or inexpensive. Business web site hosting often has a higher expense depending upon the size and type of the site.

Single page hosting is generally sufficient for personal web pages. A complex site calls for a more comprehensive package that provides database support and application development platforms (e.g. PHP, Java, Ruby on Rails, ColdFusion, or ASP.NET). These facilities allow customers to write or install scripts for applications like forums and content management.

The host may also provide an interface or control panel for managing the Web server and installing scripts, as well as other modules and service applications like e-mail. Some hosts specialize in certain software or services (e.g. e-commerce), which are commonly used by larger companies that outsource network infrastructure.

Reliability and uptime

The availability of a website is measured by the percentage of a year in which the website is publicly accessible and reachable via the internet. This is different from measuring the uptime of a system. Uptime refers to the system itself being online, however it does not take into account being able to reach it as in the event of a network outage. A hosting provider’s SLAs may include a certain amount of scheduled downtime per year in order to perform maintenance on the systems. This scheduled downtime is often excluded from the SLA timeframe, and needs to be subtracted from the Total Time when availability is calculated. Depending on the verbiage of an SLA, if the availability of a system drops below that in the signed SLA, a hosting provider often will provide a partial refund for time lost.

Many large companies that are not internet service providers need to be permanently connected to the web to send email, files, etc. to other sites. The company may use the computer as a website host to provide details of their goods and services and facilities for online orders.
Free web hosting service
Shared web hosting service
Reseller hosting service
Dedicated hosting service
Managed hosting service
Colocation web hosting Service
Cloud hosting
Clustered Hosting
Grid Hosting
File hosting service
Image hosting service
Video hosting service
Blog hosting service
Paste bin
Shopping cart software
E-mail hosting service

Obtaining hosting

Web hosting is often provided as part of a general Internet access plan; there are many free and paid providers offering these types of web hosting. A customer needs to evaluate the requirements of the application to choose what kind of hosting to use. Such considerations include database server software, scripting software, and operating system. Most hosting providers provide Linux-based web hosting which offers a wide range of different software. The web hosting client may want to have other services, such as email for their business domain, databases or multimedia services. A customer may also choose Windows as the hosting platform. The customer still can choose from PHP, Perl, and Python but may also use ASP .Net or Classic ASP. Web hosting packages often include a Web Content Management System, so the end-user does not have to worry about the more technical aspects.