What is an integer?

Answer 1

A whole number.
Can be positive /negative/zero

like 1, 5, 28, 500
-4, -63, -4853
0

but numbers like 2.5, 0.033, -45.86 etc. are not integers.

Answer 2

An integer  is a whole number (not a fractional number) that can be positive, negative, or zero. Examples of integers are: -5, 1, 5, 8, 97, and 3,043. Examples of numbers that are not integers are: -1.43, 1 3/4, 3.14, .09, and 5,643.1

int is used for declaring integer variable. For example:

int id

The size of int is either 2 bytes(In older PC's) or 4 bytes. If you consider an integer having size of 4 byte( equal to 32 bits)..

Answer 3

An integer is any real whole number. (A number without any fractional part) Such as:
1
23
1024
-8
1000024
-4083
etc

Answer 4

A number without a decimal part, maybe positive, negative or zero.