This document provides an overview of steganography, including its definition, history, differences from cryptography, techniques used, and applications. Steganography involves concealing secret messages within ordinary files like images, audio, or video in order to hide the very existence of communication. Common techniques include least significant bit insertion and substitution. While steganography can benefit covert communication, it also enables malicious uses and is vulnerable to steganalysis attacks aimed at detecting hidden messages. The document outlines both advantages and limitations of steganography.