Activity level

MFP uses a different method for estimating activity level than a TDEE calculator does. MFP's model does not include purposeful exercise - they want you to log those calories separately and eat them back. So, a desk jockey who runs 8mi per day is Sedentary, while a landscaper who does no purposeful exercise is Very Active.

Not Very Active/Sedentary: you spend most of your waking hours sitting down; if you work, your job is probably a desk job, or maybe a delivery driver of some kind.

Lightly Active: you spend most of your waking hours standing up, but not walking around very much - people caring for a small child probably fall into this category; if you work, your job is probably something like cashier, teacher, etc. (If you're a delivery driver, you might be Lightly Active on a very busy day.)

Active: you spend most of your waking hours standing, and you're walking around fairly often - people caring for multiple small children probably fall into this category; if you work, your job is probably something like retail, foodservice, etc.

Very Active: you spend most of your waking hours walking around, possibly carrying heavy stuff; if you work, your job is probably something like warehouse stocking, construction, cleaning or painting, landscaping, etc.