You can copy formulas to use them in different cells of the same sheet. When you copy a formula, you can make the formula refer to the original data or different data. When you copy formulas, your spreadsheet adjusts any relative and mixed references in the copied formulas. Your spreadsheet does not adjust absolute references.
Controlling how a formula refers to data describes how to work with formula references when you a copy formula. More power with formulas describes all the basic parts of a formula and the different types of formulas.