> For the complete documentation index, see [llms.txt](https://glados-2.gitbook.io/clight/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://glados-2.gitbook.io/clight/reference/program-structure.md).

# Program Structure

A program can be divided into multiple components, which are external declarations that include function definitions and identifier declarations.

*`program`*:\
 *`external-declaration`*

*`external-declaration`*:\
 [*`function-definition`*](/clight/reference/functions/function-definitions.md)\
 [*`declaration`*](/clight/reference/declarations-and-types.md)<br>