# Constants _Constants_ are definitions which provide a name and explicit type for some [value](values.md). The `const` keyword (definition type) is used to define a constant. ``` const weak_pi: Float64 := 3.14 const my_name: String := "Pat" ``` In general: ``` const : := ``` ## Restrictions Constants are subject to the following restrictions: - Constants MUST refer to a literal value. - Constants MUST have an explicit type. - Constants MAY refer to a record instance. - Constants CANNOT require a type constructor. - Constants CANNOT refer to functions. - Constants CANNOT refer to expressions.