The expression "2 + 2" represents a simple mathematical operation known as addition. In this case, the number 2 is added to another 2, resulting in a total of 4. This operation is fundamental in arithmetic and is often one of the first concepts taught in mathematics. Addition is a basic skill used in everyday life, such as counting objects or calculating totals. For example, if you have 2 apples and receive 2 more, you can find out how many apples you have in total by performing the addition: 2 + 2 = 4 apples.