Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
In programming languages like Java, keywords are reserved words with predefined functionality. They cannot be used as identifiers (variable names, class names, etc.) because they have a specific purpose within the language.
Related terms
reserved word: A reserved word is a term used interchangeably with keyword. It refers to words that have predefined meanings in programming languages.
identifier: An identifier is a name given to entities such as variables, methods, classes, etc., in programming. Unlike keywords, identifiers are user-defined and should not clash with reserved words.
syntax: Syntax refers to the set of rules that define how code should be written in order for it to be considered valid by the programming language's compiler or interpreter.