There are limits to how much you can invest in any tax year. For 2011/12, the limit is £10,680. Of that, the maximum you can invest in cash is £5,340 and the balance of £5,340 can be invested in shares (individual company shares or investment funds). If you don’t take the cash ISA allowance, you can invest up to £10,680 into a stocks and shares ISA.
Stocks
In the UK, stocks are fixed-interest securities such as corporate bonds and government gilts. In the US, stock is the most widely used term for shares; a diminutive of the term “common stock”.
ISA
Invidivual Savings Accounts were introduced on 6 April 1999 to replace personal equity plans (PEPs) and tax-exempt special savings accounts (TESSAs) with one plan that covered both stockmarket and savings products, the returns from which are tax-exempt. The ISA is not in itself an investment product. Rather, it’s a tax-free “wrapper” in which you place investments and savings up to a specified annual allowance where the returns (capital growth, dividends, interest) are tax-exempt (you don’t have to declare ISAs and their contents on your tax return). However, any dividends are taxed within the investment, and that can’t be reclaimed.