What does small cap and mid cap stocks mean?

All this refers to is the market capitalization of the companies. There are ranges for the different types of 'cap', see below:

- Small cap are stocks that are generally between $250 (or $300) million and $1 Billion (or $2 Billion)
- Mid cap between $1 Billion and $10 Billion
- Large Cap $10+
- Micro Cap $50-$200(or $300) million

The reason why there are ranges is because various brokers may define the ranges differently. Overall, it is pretty standard.

cap refers to the market capitalization of the stock. this is the dollar value of the shares outstanding. this is calculated by multiplying the closing market price by the number of outstanding shares. this decides the size of the company. if all the firm's market cap is calculated and listed in ascending order, u will clearly see shares which have high market cap and low cap. small cap refers to firms which have very small market capitalization for the day and mid caps is the ones which are between small and large cap. so large/small/mid cap means the size of the company as per market value.