Think of ambulatory care like going to a doctor's office for a check-up. You don't have to stay in the hospital, you just visit and then leave when you're done. This is called "outpatient care" because you're not being admitted to the hospital as a patient to stay overnight.
Ambulatory care is basically the same thing but for more serious medical needs. You go to a special clinic or medical center to get treatment or procedures done, but you still get to go home afterward.
This way, you can still get the care you need without having to stay in the hospital for a long time. Ambulatory care centers can handle a lot of different medical needs, from simple check-ups to complex surgeries.
So, ambulatory care is like going to see a doctor, but for more serious needs that can be taken care of without staying overnight in the hospital.