Most new members ask the same thing at the end of their trial day: hot desk or fixed desk? (sample)
A hot desk is any round seat at the long bench or in the quiet room. You bring your laptop in the morning and take it home at night. If you come in three days a week or fewer, it is usually the better deal.
A fixed desk is one of the squares, F1 to F12. Your screen stays set up, your chair stays at your height and the locker is full height. People who come in every day tend to move to one within two months.