Which programming concept allows the grouping of code blocks?

The concept that allows for the grouping of code blocks is block structures. In programming, block structures refer to a way of organizing code into blocks, which can contain variables, statements, and even other blocks. This organization promotes readability and maintainability of code by allowing developers to encapsulate functionality within a defined scope. Block structures often utilize braces or indentation to delineate these code blocks, making it clear where a specific section of code begins and ends.

This organizational principle is fundamental to many programming languages, including C, Java, and Python, where block structures are used frequently in functions, conditionals, and loop constructs. By using block structures, developers can manage scope effectively, control access to variables, and enhance modularity in their code.