In the creation of computer networks data communication has proven to be very essential. Before networks were invented, data had to be carried physically from a device to another. Digital networks have not only made this much easier, but they have also allowed us to transfer data much faster. The entire computer industry has been driven by this ability, including innovations of software and also the formation of the internet as a means of communication for use by both the public and professionals. As the industry continues to grow, so does the number of people connecting to these networks, which results in an exponential increase of the scope.This volume on computer networks and data communications provides a wide range of knowledge on all the aspects involved in this topic. It contains ten chapters providing insights on the manner in which we are able to maintain the main characteristics of a communication system: communication between two or more people, the ability to exchange ideas, the ability to communicate directly or indirectly, the ability to utilize both words and symbols, and finally avoiding errors occur during the process of transmission.