A total institution is a place where lots of people live, eat, work, and sleep all the time. When you go to a total institution, they take away a lot of your choices and control your life. You have to wear certain clothes, eat certain foods at certain times, and do everything exactly the way they tell you to.
Places like prisons, military boot camps, and some types of hospitals are examples of total institutions. When you're in a total institution, you can't leave whenever you want, and you can't really make your own choices about what you do or how you live your life. Instead, the people who run the institution make all the rules and control everything you do.
Even though it might seem scary, some people actually like living in total institutions because they feel safe and protected. But for others, it can be really hard because they feel like their freedom and independence are being taken away.