Integer
An integer has no figures after decimal point
... , –4 , –3 , –2 , –1 , 0 , 1 , 2 , 3 , 4 , ...
The set of integers is denoted by the symbol Z (comes from the German word "Zahl").
Explanation
The integers have an order, but no bottom or upper limit. The set of integers has as many elements as the set of natural numbers, and are both countably infinite.