Lets starts with the basics. There may be time when you start to think, what if the Internet did not exist? Would life be the same without your favorite websites, email or social networks. At the click of a mouse you can surf the Internet but wait a minute… the resources which you are accessing are surely not localised near you. They are found somewhere out there, in some other countries and you can access them within few seconds. Awesome, right?
So, what is Network? I’ll put some light on the basic terms of networking.
WAN vs. LAN
There are a lot of types of network but the mostly used are
Local Area Network (LAN) and
Wide Area Network (WAN)
Local Area Network, as its name suggests, is found within your local area. For example several computer connected at your workplaces, your home with several devices connected become the LAN.
Wide Area Network is when resources are localized on a distant computer (like other country), to access which you need several communication lines. See the figure below.
The million dollar question! So what is Internet? Is it a LAN or a WAN or some other fancy architecture?
Well, the Internet is simply several LAN interconnected by WAN just like shown in the figure 1.
Network of computers is classified by 3 properties: which is topology, protocols and architecture.
This is simply the arrangement of computers in the network, and the way they communicate to each other. Example of topologies are: star, ring and bus.
Star – “Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer, which act as a conduit to transmit messages. This consists of a central node, to which all other nodes are connected; this central node provides a common connection point for all nodes through a hub. In star topology, every node (computer workstation or any other peripheral) is connected to a central node called a hub or switch. The switch is the server and the peripherals are the clients. Thus, the hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star.” – Wikipedia.
Ring – ”A ring network is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node – a ring. Data travel from node to node, with each node along the way handling every packet.” – Wikipedia
Bus – ”A bus network is a network topology in which nodes are connected in a daisy chain by a linear sequence of buses. The bus is the data link in a bus network. The bus can only transmit data in one direction, and if any network segment is severed, all network transmission ceases. A host on a bus network is called a station or workstation. In a bus network, every station receives all network traffic, and the traffic generated by each station has equal transmission priority.” – Wikipedia
Protocols are just a common set of rules and agreement between 2 communication parties. They are guidelines which need to be followed in order to allow computers to communicate on a network. Example protocols are:
Architecture can be broken into 2 major parts: p2p (peer-to-peer) and client-server.
Peer-to-peer. No server exist, and computer simply can connect with each other in a workgroup to share files, a printer or Internet. The most common example of this architecture are networks used for sharing files in a P2P manner like eDonkey, BitTorrent and for voice communication like Skype.
Client-server. This architecture is commonly used. Let’s say you want to access itcuties.com, that is why you enter http://www.itcuties.com in your browser window. Your computer sends the request to our HTTP server. Then, the server does the processing – in our case, get data from database. After server finishes processing your request it sends you the response back, which in our case is HTML page containing data from our database.