The internet as we know it today was a small network of a few computers, linked together in a small area. Limited amount of data transfer was possible. Slowly but gradually, this network grew bigger and more complex, where more amounts of data communication was possible and with greater ease. Of late, this network has grown into the internet as we know it today. Today data as well as voice communications are possible and with such an ease as never before. All this has been possible because of computer networking.
Computer networking is a way of communication between computers, wherein computers are mutually connected either with wire or wirelessly. Various standards known as "protocols" have been developed by the IEEE for computer networking. Two or more computers follow these protocols to communicate with each other, either in a wired manner or wirelessly.
It requires many electronic devices like routers, network hubs, separators, etc. Many companies like CISCO, NETGEAR, etc. have come up which provide these networking instruments. As a result many lucrative jobs in these sector have come up. Some of these companies like Cisco, provide their own certifications like CCNA, CCNP and CCNE, which are recognized as industry standards worldwide.