Error control coding is an indispensable part of any digital communication system. In this introductory course, we will discuss theory of linear block codes, their encoding and decoding techniques as well as their applications in real world scenarios. Starting from simple repetition codes, we will discuss among other codes capacity approaching low density parity check codes. We will also discuss bounds on number of codewords given codeword length and minimum distance of code. (from nptel.ac.in)