# 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`*](https://glados-2.gitbook.io/clight/reference/functions/function-definitions)\  [*`declaration`*](https://glados-2.gitbook.io/clight/reference/declarations-and-types)