Cell Range: Two or more cells in a spreadsheet.  In Spread Formulas, use a colon ":" between 2 cell references to specify a range.  Example: AVG(C5:C11)

Absolute vs relative references

When referencing to cells in formulas you can refer to the cell with an absolute ($A$1) or relative (A1) reference.  This only effects when you copy (or drag and drop) the cell with the formula.

Absolute:  In a formula, the exact address, regardless of the position of the cell that contains the formula. 

Relative: In a formula, the address of a cell based on the relative position of the cell that contains the formula and the cell referred to.  If you copy the formula, the reference automatically adjusts.