Literals are types that refer to specific strings and numbers. They can be combined into unions to create types that only allow for a selection of strings or numbers. This can be useful for restricting propertys to specific values, such as fontWeight only accepting bold, bolder, etc.
There are string literals and numeric literals
type alignment = 'left' | 'middle' | 'right' type fib = 1 | 2 | 3 | 5 | 8