What is defined as the very rigid rules governing the structure of a program?

The term that describes the very rigid rules governing the structure of a program is syntax. Syntax refers to the set of rules that defines the combinations of symbols that are considered to be correctly structured programs in a programming language. Just as grammar structures sentences in human languages, syntax structures the code, ensuring that it complies with the rules of the programming language being used.

If the syntax is not followed, a program will not compile or run as intended, resulting in errors. Understanding syntax is essential for writing code that the compiler or interpreter can understand, which differentiates between valid and invalid statements. This aspect is fundamental to the way programming languages operate, as it establishes how various elements (like variables, operators, and control structures) can be combined to create functioning software.

While semantics relates to the meaning behind the syntax and how it should behave, and logic involves the flow and reasoning within programming constructs, formatting focuses more on the organization and presentation of code rather than the structural correctness defined by syntax.