JPM PB v. AM - what’s the difference?

Extremely inaccurate. 

The Private Bank is ultra-high net worth wealth management.

On the partner coverage side, you work with family offices of billionaires/500mm+ families on specific sleeves while generally owning the bulk if not all of the wealth management of individuals in the sub 300mm net worth. In all essence the client facing roles (investment specialists/bankers) are sales/relationship management/investment relations esque responsiblities. The banker is the key sales driver in these relationships wining and dining clients and trying to bring in new money. The investment specialist while having some leeway is generally the spokesperson for the investment engine in the investment solutions side of the business communicating the views of the bank to clients. Moreso being extremely knowledgeable about positioning, super high level asset allocation. 

Single coverage works with sub 25mm net worth clients and this generally extremely sales focused as you work primarily with clients with relatively simple balance sheets. More lucrative than partner coverage as there are many more clients in the space. 

The investment solutions arm of the PB is essentially overseeing and building all unique investment engines that clients can access. There are CIO teams which create and build portfolios that clients across the PB can invest in (and whose views the investment specialist communicates), diligence teams that handle onboarding external managers, marketing teams etc. 

Asset Management is a completely different business. Here you work directly with/on the JPMAM mutual funds/etfs and work with clients like SWFs, large pensions like Calpers, smaller RIAs (that coincidentally could compete with the PB). Very limited interactions with individuals and almost entirely with institutions. Basically the same as if you were working for a buyside shop like Wellington, PIMCO, etc. on their mutual funds. The three key roles here are portfolio managers who directly manage the funds, investment strategy folks who work with the portfolio managers hand in hand on portfolio matters and sales side, and salesman whose sole mandate is to sell the funds/etfs to institutions.