ampersand
The sign &, which stands for and.
In running prose, write and. Use an ampersand only where it is part of a name or an established abbreviation. That includes company names, such as Procter & Gamble and Barnes & Noble, and abbreviations such as R&D and Q&A. Where space is limited, as in tables, charts, and headings, an ampersand may replace and. Within one document, use the same form for the same kind of pairing.
Examples
UseThe company spent more on R&D this year. (The ampersand is part of an established abbreviation.)
UseThe report was written by Johnson and Patel. (In running prose, and joins the two names.)
AvoidThe report was written by Johnson & Patel. (The two names do not form a company name, so write and.)