The most common way of saving is into a bank account (‘deposit’ account) where the money can be accessed in an emergency, and for every £1 you put in, you will get £1 back and possibly some interest. In other words, the original capital is guaranteed.
Investments are designed to be held for a longer term, usually at least five years. You need to be comfortable with tying up this money for a period of time and should not consider investments unless you have some savings in place. Most investments are not guaranteed to return your money in full, although do offer the prospect of potentially higher returns than deposit accounts. Returns, risk and volatility are the factors that will determine a suitable place for your investments.
The value of investments may fall as well as rise. You may get back less than you originally invested.