What are sub-range types and sub-types in Pascal language?

What are sub-range types and sub-types in Pascal language?

- The sub-range allows defining the implementation of the functions that provides the data conversions to be performed on the data types like real to integer, etc.

- The sub-ranges of the data type can be made using the ordinary data type which will be as follows:
var
x : 1..10;
y : 'a'..'z';
z : Apple..Mango;

- Set provides a way to group the things and the objects using the mathematical algorithm. The set can hold the values that will make it faster.

- The set types are used to have a set in which there are some values that needs to be defined.

- This is shown as:
var
Set1 : set of 1..10;
Set2 : set of 'a'..'z';
Set3 : set of Apple..Mango;

- Set operators can be used to implement the machine code operations that involve smaller domains.