So confit is a way of cooking things, and it does marvellous things to many things.
You put stuff in oil and slow cook it. That’s confit. Garlic confit? Put it in oil and slow cook it. Chicken confit? You put it in oil and slow cook it.
(side note: confit historically means to preserve by cooking at a low temperature, (which often also meant a cure prior to cooking). So Fruit confit is fruit that’s been cooked at a low temperature in a very concentrated sugar solution, not in oil. Nowadays, confit usually just means cooking slowly in oil outside the context of fruit and does not imply a curing process)
Compared to deep frying, almost no moisture is lost, and the flavour is not changed via the maillard process because it doesn’t happen. There is no charring or searing done to the meat/whatever you’re confitting.
For veg in general, to confit them will cause them to become ultratender, as fibers and stuff will partially break down, cell walls will collapse, but no moisture will be lost. And their flavour will mostly remain; for garlic in particular, the hot garlicky taste, the result of the allicin, which is a result of crushing or chopping the garlic, will never come out. The chemicals will break down under that amount of heat.
The oil does not terribly seep into the food by the way; it’s already saturated with water, and unless that water leaves, the oil doesn’t have a place to seep into. It’s saturated already, and the result of connective tissue breaking down, or fibres breaking down, is less room for fluids. Which is why a carrot can be nice and dry, go into a hot oven, and come out floppy and moist, as the water inside can no longer be held by its inside, and available, unabsorbed water = wet.
You do get a thin layer of oil coating the outside of the food.
This means that confit’ing a food item is actually very close to steaming that item at a particular temperature, or cooking it sous vide; in either case, the item does not dry out and slowly reaches its final temperature.
