A program consists of English-language instructions called source code . The syntax for these instructions is strictly defined by the language.

In C#, source code consists of a series of statements. A statement is an instruction to the compiler. Each instruction must be formed correctly, and one task you’ll face when learning C# will be to learn the correct syntax of the language. For example, in C#, every statement ends with a semicolon.

Each instruction has a semantic meaning that expresses what you are trying to accomplish. Although you must follow the rules of C# syntax, the semantics of the language are far more important in developing effective object-oriented programs. This book will provide insight into both the syntax and the semantics of good C# programs.