Prison experience depends on many factors such as the length of sentence, the offence you committed, your background(like are you socially well connected with other prisoners), and your general risk of escape/ danger to other inmates or staff.
Prisons are usually categorised in security ratings and since it costs far more to put prisoners in the higher security jails your security risk is carefully assessed.
There are differant rules applying to differant inmates in terms of sentence management.
An ordinary Joe who does something like Drink Driving, holds a job down, family etc, not a career criminal will usually end up in very low security rated prisons. Such a person might end up working in the community during the day, or in Norway and in experimental US schemes you do your jail at weekends only thus you keep your job and family contacts and lessening the risk of going the whole way into a life of crime.You can get by without much grief but there are many factors, usually trouble goes looking for those who want to find it.
If you are the more run of the mill type offender then we are talking about burglary, maybe to feed a habit, perhaps some violence but not with particularly serious results, possibly having been in fairly regular contact with law enforcement agencies, maybe little or no work skill and low educational levels then you would end up in middling security rated prisons.
You would be required to take some part in planning your sentence which would mean addressing your core failings and would be expected to take part in correcting them.
This might mean detox to come off drugs, it could be education where you would have to succesfully complete a number of courses, you might have to do courses to teach your how to control your emotions and the way you approach lifes challenges.
You may also be required to carry out work related training.
Failure to do these would mean that you would have to serve longer in jail and maybe have a more Spartan way of life as you will not have earned extra privelidges.
The high security inmate will do loads of education or skill training but it is mostly voluntary, work is often voluntary, with a person who has nothing to lose, coercion does not work well.
Sex offenders or child molesters may be compelled to do sex offender behaviour programs, and in some cases they may never be released until this has been done succesfully.
Now as for life in jail itself -
The first thing to note is that you have absolutely no privacy whatsoever, you may be strip searched, all your letters read, required to pee in a bottle for drug tests, you cell will be searched regularly, you may be moved from jail to jail at no notice at all, your visitors - family, girlfriends, parents etc will be closely scrutinised and if there is good cause they too may be strip searched to prevent drugs mainly but also guns from getting into jail.
This breeds an atmosphere of persecution, it is fairly common for inamtes to become clinically depressed and cut themselves, a few will make genuine attempts to commit suicide.
As you get into the routine of jail life you will associate with others who have common needs or interests.As a drug user you might find yourself doing the running for dealers just to get what you need or you may be used to collect debts.Prisoners build up a fragile trust between each other as it is incredibly difficult to cope on your own for all sorts of reasons and not just for protection as you might expect but also in simple human needs like someone to talk to.
If you are not a drug user you are usually left pretty much alone(but sometimes you may have to hold drugs for dealers as you are less likely to be searched and less likely to steal from the stash) but when you are down(and it happens to most inmates) you might well be offered drugs by a dealer “just to help you out” often for free.Your chances of getting a real serious habit are not great since drugs are so expensive and poor quality in jail but you will get into debt.
Look at it from the dealers point of view, he lends you something and he will expect twice back - he can’t afford to let you off the hook or he is finished, other inamtes will notice so now he owns you.Generally you get knocked around a bit, black eye, few bruises.
If you don’t fight back then this will be noticed by other inmates and you may become vulnerable to much more brutal intimidation.Some have to do whatever it takes but it is rare.
Child molesters, sex offenders generally, those who attack and rob the elderly, and informants can expect special treatment meted out if they are discovered. They usually keep their heads well down and may request custody in vulnerable prisoner units.
If you are a jerk in prison it will be painful, you always have to think about what you say, you always have to think about the impression you create in the minds of other prisoners there are many actors worthy of Oscars in jail.
The whole thing is like a game where you try to win a few here and minimise your losses elsewhere, sometimes you get one over on the staff, sometimes they get one back.
The movies are, as you might expect, largely an exaggeration of what goes on, the vast majority of prisoners just want to get their time over and get out.
I’m not saying that terrible things do not happen but it is not as common as is made out.
I could go on for ages about jail life but I’d better give someone else a turn.