A computer network is a digital telecommunications network that allows the exchange of resources across nodes. These can be personal computers, servers, phones or networking hardware. The connections between these nodes are established over wireless media, optic cables or wires. The protection of digital data from unauthorized access and actions is called data security. Cyberattacks and data breaches can cause unwanted changes to data. Disk encryption, backups, data erasure, data masking, etc. are some of the technologies generally employed to ensure data security. Network security is an important consideration in data security. It is used on both private and public computer networks. This book explores all the important aspects of data security and communication networks in the present day scenario. It outlines the processes and applications of these fields in detail. This book, with its detailed analyses and data, will prove immensely beneficial to professionals and students involved in this area at various levels.