This textbook provides a firm foundation for those studying the field of error control codes. giving step-by-step instruction on this complex topic beginning with single parity code checks and repetition codes. Through these basic error-control mechanisms the fundamental principles of error detection and correction, minimum distance and error-control limits are considered. With the use of detailed examples it guides students from basic error-control codes through linear codes, cyclic codes, linear feedback shift registers, vector fields, Galois fields, BCH codes and convolutional codes. There are many detailed examples throughout the book to illustrate the principles and complex mathematical proofs are omitted where possible to keep the text concise and easy-to-follow.