Integers are the collection of whole numbers and their negatives. There are two types of integers: positive integers like 1, 2, 3, etc. and negative integers like -1, -2, -3, etc. Integers are ordered on the number line, with positive integers to the right of zero and negative integers to the left. Addition and subtraction of integers follows sign rules - integers with the same sign are added/subtracted normally, and integers with different signs are subtracted but keep the sign of the larger integer. Integers are used in daily calculations like balances that can be positive or negative. Multiplication and division of integers also follows consistent sign rules.