Creating data types and re-naming types is powerful. To achieve both things, PureScript offers two keywords: Using "Type" we can alias existing types. Using "Data" we can define custom data types.
This keyword helps to reference existing data types.
type MultipleChars = String
someString :: MultipleChars
someString = "Hello world"
It is also used to create the type definition for records and other complex structures.
The data keyword is a little bit more complex. On the left-hand side, we have the actual data type. On the right-hand side of the equals-sign is the so-called data constructor. Custom data types must always start with an uppercase letter.
data MyDataType = MyDataType
Default types like Boolean can be written with the data keyword, even though this will collapse with the existing type.
data Boolean = True | False