The syntax of the Terraform language consists of only a few basic elements:

Blocks are containers for other content and usually represent the configuration of some kind of object, like a resource. Blocks have a block type, can have zero or more labels, and have a body that contains any number of arguments and nested blocks. Most of Terraform’s features are controlled by top-level blocks in a configuration file.

Arguments assign a value to a name. They appear within blocks.

Expressions represent a value, either literally or by referencing and combining other values. They appear as values for arguments, or within other expressions.