(This article is part of a series network-basics)
So you want to make a computer to “talk” to another computer? Here the word “talking” would mean using some communications protocol (we are interested in the Internet Protocol) to make these computers to send data packets to each other. These packets will amount to chat messages, electronic mail and transferring a file from one machine to another and many more things.
A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections. Data is transferred in the form of packets. The connections (network links) between nodes are established using either cable media or wireless media. The best-known computer network is the Internet.
In computer networks you would expect to find sometimes “peers” communicating with each other and sometimes a server “serving” a file or other service to a client computer.
Computers (and other hosts such as smartphones, tablets, M2M etc) use networking-specific hardware to connect to network devices, such as Wireless Access Points and wired Switches. These first devices are typically called Local Area Networks (LAN). They are usually connected in some way or another to larger complexes called Wide Area Networks (WAN), via Routers and/or Firewalls.
As the names imply, a Local Area Network would cover the area of a single department’s office, a corporate site or a home. Wide Area Network refers to a nationwide/worl-wide network of corporate offices or The Global Internet.
Computer networks in general can be used for multiple applications and they also come with their security concerns; when a computer is a network, it can be accessed by other computers, in one way or another.