CONCATENATE can join up to 30 text items together.
Text items can be text strings, numbers, or cell references that refer to one cell.
Numbers are converted to text when joined. If you need to specify a number format for a number being joined, see the TEXT function.
The ampersand character (&) is an alternative to CONCATENATE. The result is the same, but the ampersand is more flexible, and creates formulas that are shorter and (arguably) easier to read.