Networking Basics - Part 1

Network Interface Card (NIC)

It is a hardware component of the computer that connects our devices such as iPad, laptop etc to the network such as Internet. It is also known as Network Interface Controller, Network Adapter, LAN Adapter and Physical Network Interface.

Network Interface Card

Example:
We have a laptop connected to the network via a cable plugged into Network Interface Card and they are called as Wired Network Interface Cards. These days, we have Wireless Network Interface Cards that enable our devices to connect to the network running in the air.

Computer Network

what is a computer network? Before understanding what a computer network is, let's think about a social networking site such as Facebook.com, Twitter.com. These sites enable people to connect to each other by allowing them to communicate with one another by sharing information such as text, video, audio etc. Similarly, a Computer Network allows devices such as a laptop, computer, iPad, iPhone etc. to communicate with one another. In its simplest form, a computer network can be 2 devices such as a laptop and a computer connected to each other via a cable sharing information with each other.

Computer Network

For example, we may have a file on our computer that we want to send to another device such as a laptop. We could connect them via a cable (Ethernet cable) which is plugged into network interface card on the computer and allow them to share information with each other.

Internet

• We all use internet on daily basis, spends hours on social networking websites such Facebook.com, Twitter.com etc. 
• The Internet provides us the ability to connect to the world through these sites. Not only does it connect people through social networking sites, but it also provides us a wealth of information through websites such as Wikipedia.org, allwomenstalk.com. 
• The Internet also enables us to shop online, thereby saving us from standing in queues in a shopping mart. What actually is an "Internet"? The definition is quite simple. 
• The Internet is a "complex/massive computer network" or we can say "Network of Networks".
• It connects millions of computers together globally and forms a network in which any computer can communicate with any other computer as long as they are both connected to the internet.

Network Protocol

It is a set of rules that govern the communication between the network devices. Let's understand it in this way. Suppose there are 2 persons A and B whereas A only speaks French and B only speaks Hindi.They will not be able to communicate effectively with each other. In a similar way, a Network Protocol can be considered as a language that devices on the network use to communicate with each other.

Small Office & Home Office Network (SOHO)

SOHO is a term used to refer small office and home office environment. SOHO network is a network that supports the SOHO work environment. Unlike large businesses, small businesses do not require large networks to support themselves and their employees.They use small networks to cater to their online needs.
Below picture depicts a SOHO network.

Small Office & Home Office Network

In our home office network, we may have a router that connects the SOHO network to the public data network (internet) via a local ISP (Internet Service Provider).The router may provide wireless connectivity so that our devices such as Laptop, iPad, iPhone etc. will be connected to the network or it may provide wired connectivity so that our desktops will be connected to the network. The router may be connected to a device called Switch.

Note:
The Router receives information from 1 device and then, decides where to forward this information based on some decision criteria. Like, shall I forward this to wireless so that it can be received by the laptop or shall I forward this to the internet in case there is a request for website access such as facebook.com? The Internet is made up of thousands of routers.

The Switch is a network device that has got multiple ports (interfaces) to which multiple devices can be connected so that all devices can communicate with one another.

Let's come back to our example of a home network, we may have a router connected to a switch. The router may be providing wireless connectivity through which our devices such as a laptop, iPad etc. will be connected to the network. We may have a network printer and PC's that are physically connected to switch.

Note:
We will discuss the network devices in detail later.