Market Cap
Short for market capitalization. It is the market value of the firm’s equity (stock). It does not include the firm’s debt (bonds). Investment professionals and the financial media often speak of micro cap, small cap, mid cap, large cap, and mega cap stocks. This simply refers to what the equity in the firm would be worth if every share was valued at the market price (i.e., the price of the last trade).
Remember, market cap does not directly measure the size of a business in any meaningful sense: sales, profits, employees, etc. Market cap can be viewed as the price tag on a business (as can enterprise value). Aside from this purpose, I have never found market cap to have any utility whatsoever.