What are the Data types of VHDL

VHDL. A multitude of language or user defined data types can be used. This may mean dedicated conversion functions are needed to convert objects from one type to another. The choice of which data types to use must be considered wisely, especially enumerated (abstract) data types. This would make  models  clearer  to  read,  easier  to  write and  avoid  unnecessary  conversion  functions  which can clutter the code. VHDL may be preferred since it allows a multitude of language or user defined data types to be used.