Connection time, and the part of it a session cannot touch
Connection time is the gap an airline allows between two flights; the minimum it sets is for changing planes, never for leaving the airport and returning.
Airlines publish a minimum connection time for each airport: the minimum gap they will sell between two flights on the same ticket. At a large hub it may be under an hour. It is designed for a passenger walking from one gate to another, and it has nothing to spare for anything else.
Minimum is not usable
A connection built on the minimum time is a corridor, not a layover. There is no version of it that includes a hotel room, and it would be unkind to suggest otherwise. A session needs a stop long enough to leave the transit area, reach a room, and come back through security with the airline's margin intact.
Choosing a longer connection
Travellers who want a session on the way through often choose a longer connection deliberately when they book the flights: a later onward departure on the same day, or one the following morning. The fare is sometimes the same. Six hours or more on the ground, with a room near the terminal, turns a connection into a stop where an hour or two fits comfortably.
Protected and separate tickets
On a single ticket, the airline takes responsibility for a missed connection, usually with a rebooking and sometimes with a hotel night. On separate tickets, it does not. A session planned on a tight connection between separate tickets carries a risk that no booking can remove. The layover entry and the missed connection page cover both situations.