In Terraform expressions, which option correctly describes the var keyword?

• A. It references a data source
• B. It defines a resource attribute
• C. It references the value of an input variable
• D. It declares a local value

Answer: (C)

In Terraform expressions, the var keyword is used to read the value of an input variable. This lets you parameterize your configuration so it can adapt to different environments without hardcoding values. You declare variables with variable blocks, then supply their values through files, environment variables, or defaults. Inside expressions you access them as var.name, for example ami = var.ami_id or region = var.region. This is distinct from referencing a data source (which uses data blocks), defining a resource attribute inside a resource block, or using a local value (which uses locals). The var keyword specifically pulls in the values provided for input variables at run time.