An ISA, or Individual Savings Account, is a type of savings account available in the United Kingdom that allows individuals to save or invest money without paying tax on the interest or capital gains earned. There are different types of ISAs, including Cash ISAs, which function like regular savings accounts, and Stocks and Shares ISAs, which allow for investment in various financial markets. ISAs have annual contribution limits, which can change each tax year. They are designed to encourage saving and investing among individuals, making it easier to grow wealth over time while benefiting from tax advantages.