Most public servants who joined on or after 1 January 2013 are in the Single Public Service Pension Scheme. It is a career average scheme. Each year you bank amounts towards a retirement lump sum and a pension, based on that year's pay, and they are increased for inflation.
Normal retirement age in the Single Scheme is the State Pension age, currently 66, with a compulsory retirement age of 70 for most members. If you joined before 2013, you are likely in a final salary scheme, where the pension and lump sum depend on your pay at the end of your career and your years of service.