Math

Integers are a special group or category of numbers that:

Consist of the set of numbers: {…-4, -3, -2, -1, 0, 1, 2, 3, 4…}
Are all positive and negative whole numbers, which do not include any fractional or decimal part.
A few things to note here:

There are no fractions or decimals in any part of the numbers
Negative numbers often represent the idea of being below a standard value.
Zero is an integer. In many other number groups whether or not zero is included makes a difference. Note that zero is included in the set of integers.
Remember that categories of numbers overlap. Just like categories of geography (ex. country, state, county, city, street) overlap each other (a street is in a certain city, which is in a certain county, which is in a certain state, etc.) categories of math overlap each other too.
Don't let the notation throw you off. The brackets ( { } )are used to write sets. This is the standard mathematical notation used when you want to list a group (or a 'set') of numbers. The ellipse ( … ) just means they go on and on forever in the same pattern. This is especially helpful when the group you are trying to represent is too big to write out in its entirety.

An integer (pronounced IN-tuh-jer) 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.