It's difficult to draw generalized comparisons across prisons, honestly, but it's also interesting to attempt to understand.
Men's vs women's prisons are incredibly different.
Within these categories, custody levels (i.e. minimum vs maximum) is very different. Contrary to popular belief, custody levels are based upon the time someone has left on their sentence (plus good behavior) and is not necessarily based on the severity of one's crime. When I worked in a minimum security prison (not as custody staff or as a mental health professional—always feel the need to add that qualifier), I worked with people who committed child rape, people who struggled with drug addiction, people charged with murder, and people who committed fraud in addition to those with crimes I don't know about. Furthermore, a facility can have mixed custody (i.e. be a minimum and medium security prison).
Additionally, private vs. state prisons are very different. While federal/state prison conditions are bad, private prisons are way exploitative and worse on operating from a perspective of punishment.
Finally, you also have things like work release where you're technically still within the prison system but are able to find and work a job.
Jails are also different and I hear have even worse conditions than prisons.
And lastly, every facility is different and every custody officer is different. Some are incredibly strict on really benign shit, while others don't care. I once watched a custody officer confront/ask an incarcerated woman what she was hiding behind her back (a cucumber for her lunch that she stole from the prisons veggie garden) and the incarcerated woman made a silly show out of dramatically hiding it behind her back and refused to show the officer, who eventually shook her head and just smiled and walked away. But with other officers that woman could have recieved an infraction.
It's all just so wild and I wish people really saw the full nuance of everything.