# types

A *type* refers to a class of data and the operations permitted on that class of data. 
The following built-in types are supported for the BBC micro:bit:

* **[String](/reference/types/string)**: a sequence of characters
* **[Number](/reference/types/number)**: an integer number (32-bit signed)
* **[Boolean](/reference/types/boolean)**: true or false
* **[Image](/blocks/image)**: a collection of [micro:bit LED states](/device/screen) (on/off)

TypeScript allows you to create user-defined classes of data.