Jeremy's calls themselves a department store, although I would consider them to be a
specialized department store. They sell clothing and accessories (including handbags), both men and women, and everything is new. They receive their items from Saks, Neiman,
Nordstrom & other high-end dept stores, and the items they receive are either overruns, slightly damaged (so they can't be sold in the high-end dept stores) or customer returns (again, so they can't be re-sold by the orig store). I believe they also sell samples from time to time. The selection is hit or miss because they don't always have the same style in every size... your timing just has to be right.
Their SF location is known to have higher-end designers than the Berkeley store. I've been to both (and recently learned that they expanded their SF location to two stories). My more recent experience was at the Berkeley store, and I remember seeing lots of J.Crew sweaters/chinos/dress pants/coats/dresses for a great price, and lots of designer names (can't think of any off the top of my head right now). I bought a cardigan there that said "Moth", which my friend just told me is from Antrhopologie.
The ambience is more like a large boutique, too small to be a dept store and too nice to be called a wherehouse. I've heard it can get pretty crazy in there when there's a sale or when a new shipment comes in!
All I know about them is what I've observed when going to their store, what I've heard from my friend and from their website, so I hope this helps...
You should make a trip to Jeremy's to see for yourself!