What does it mean for a keyword to be highlighted in a programming environment?

Highlighting a keyword in a programming environment signifies a reserved word. Reserved words, or keywords, are predefined words that have special meaning in a programming language, and they cannot be used for any other purpose, such as naming variables or functions.

When developers write code, keywords like "if," "else," "while," and "class" play crucial roles in dictating the structure and flow of the program. Their highlighting helps programmers quickly identify the core elements of the language's syntax, making the code more readable and helping prevent errors in code structure or logic.

The highlighting serves as a visual aid that distinguishes these reserved words from identifiers like variable or function names, which have different purposes and rules for naming. This distinction is vital for maintaining clarity and understanding within the programming code.