#30 – Types, Variables, Values, Instances

In C#, a type dictates what kind of values can be stored in a variable.  A variable is a storage location for some data.  Every variable is an instance of a specific type and will have a value that can change during the lifetime of a program.

Constants are variables whose values do not change.  They also have a specific type.

Expressions resolve to a particular value when they are evaluated.  They also have a specific type.

There are a number of built-in types in C#  (e.g. int, float) as well as constructs that allow you to create your own types (e.g. class, enum).