What term refers to the set of rules that defines the correct structure of a programming language?

The term that refers to the set of rules defining the correct structure of a programming language is syntax. Syntax encompasses the specific guidelines regarding how code must be written for the programming language to be understood by the compiler or interpreter. This includes things like how to declare variables, the correct use of punctuation, the arrangement of keywords, and the overall format of statements.

For instance, in Python, the syntax dictates that indentation is significant for defining code blocks, while in languages like Java, braces are used to structure the code. Understanding syntax is crucial for writing programs that function correctly, as any deviation from the established rules can lead to errors in compilation or execution.

The other terms do not define the structure of a programming language. An algorithm describes a step-by-step procedure for solving a problem, runtime refers to the phase when a program is executed, and structure might imply the organization of code but does not specifically relate to the rules governing how that code is written.