Computer networks are a fundamental part of computer science. It enables computing devices with networks to share information with each other by using data links. The most common devices which use the computer network technology are servers, desktops, laptops, mobiles, etc. Computer networking is also important because it helps in allowing access to digital audio, world wide web, fax machines, digital video, printers, etc. to the network devices. This book studies, analyses and upholds the pillars of computer networking and its utmost significance in the modern times. For all those who are interested in this field, this textbook can prove to be an essential guide.