BNF Notation, or Backus-Naur Form, is a formal way to describe the syntax of programming languages and data structures. It uses a set of rules to define how symbols can be combined to form valid statements or expressions. Each rule consists of a left-hand side, which is a non-terminal symbol, and a right-hand side, which shows how that symbol can be constructed using other symbols. This notation is widely used in computer science for designing compilers and interpreters. By providing a clear and concise way to specify language grammar, BNF Notation helps developers understand and implement programming languages more effectively.