What are Defined Benefit and Final Salary Pension schemes?

These are usually  workplace pensions  arranged by your employer. They’re sometimes called ‘final salary’ or ‘career average’ pension schemes. 

How much you get depends on your pension scheme’s rules, not on investments or how much you’ve paid in. Workplace schemes are usually based on a number of things, for example your salary and how long you’ve worked for your employer. 

More info - https://www.gov.uk/pension-types