An integer is a number without a decimal point – a whole number. Integers are good for problems like counting. Some problems, like counting every person on the planet, require really large numbers. Other problems, like counting the number of children in a classroom, require numbers that aren’t as large.

To address these different problems, integer variables come in different sizes. An integer variable has a certain number of bits in which it can encode a number, and the more bits the variable has, the larger the number it can hold. Typical sizes are: 8-bit, 16-bit, 32-bit, and 64-bit.

Similarly, some problems require negative numbers, while others do not. So, integer types come in signed and unsigned varieties.