A mortgage is a loan to buy a property. The size of mortgage one can take out is usually in proportion to income. First time buyers can take out a mortgage at 5 times income. For example if you earn 30 thousand pounds a year you can take out a 150 thousand pound mortgage.
Banks are offering 20 year mortgages at just 4.25%. This is the lowest in 5 years. When rates are this low many people take out fixed rate mortgages so that the rate stays at this low rate. Although house prices are very high , low mortgage rates have helped many first time buyers get on the property market. However with london property prices at over 200,000 pounds its still very hard to get on the property ladder.
The government is trying to make banks lend more money for mortgages.