What does it do? Although the public may still think, like Ronnie Barker's famous Porridge character, that prison is a place where "villains are banged up," the task of today's Prison Service goes far wider. The current wording of its role is to "serve the public by keeping in custody those committed by the courts...and help them lead law-abiding and useful lives in custody and after release." There are 130 prisons spread around the country, organised into 13 regional divisions, plus a separate structure of nine high security establishments, such as Parkhurst on the Isle of Wight. A couple of years ago, the organisation was merged with the sister body, the Probation Service, which monitors prisoners after release, to form the National Offender Management Service.

Vital statistics:T he prisoner population fluctuates and currently stands at 76,000. Watching over them are 47,000 staff, of whom 19,000 are uniformed officers, and 1,300 are management, or governor, grades.

The office: For most prison officers, of all ranks, the office is their own particular prison, but big decisions are taken at head office, at Cleland House, in Westminster's political village.

Is this you? The Prison Service website ( www.hmprisonservice.gov.uk) shows graduate opportunities in a number of specialist areas, including psychology and pharmacy, but the main recruitment route for future managers is the Intensive Development Scheme (IDS), which takes up to 18 graduates a year. Any degree will do, alongside a real interest into the workings of the criminal justice system.

The recruitment process: Recruitment to the IDS starts in the autumn, and around 650 applications are received every year. The key stage in the process is a two-day assessment centre exercise, which focuses on the interpersonal skills so crucial to any job in a prison. The first year of training covers the role of prison officer on a wing. You gain a thorough grounding in the day-to-day operation. The second year covers promotion to senior officer, with some managerial responsibility, and in the final year on the scheme, graduate recruits assume a governor grade, with managerial responsibility for one of the various prison functions, such as resettlement or security.

Top dollar? Starting pay is in line with that of a regular prison officer, at around £17,500. This rises to around £27,000 as a senior officer, and £32,000 as a junior operational manager.

Beam me up Scotty? Many senior governors started as graduate trainees. The widening of the criminal justice system has also brought opportunities to move into senior management roles outside the prison system.

Who's the boss? Phil Wheatley, the Director General, has already done a 36-year stretch in the prison service. Before his appointment two years ago, he was in charge of all high security prisons.

Little known fact: Private sector involvement has been present in the Prison Service since the 1990s. Eleven prisons are now privately managed, among the biggest Doncaster Prison, which holds 1,100 male inmates.