This document provides an overview of modern forward error correction (FEC) techniques used in satellite communications (SATCOM). It discusses the motivation for using FEC to combat various link impairments. It then reviews various FEC schemes including block codes, convolutional codes, turbo codes, and compares their performance. Turbo codes are shown to provide the best performance, approaching the theoretical Shannon limit, allowing for reduced transmitter power and bandwidth compared to older FEC schemes. The document concludes that while newer codes like turbo codes offer close to optimal performance, simpler block and convolutional codes also provide good performance for their lower complexity.