First, from what I have learned, there are some people who get annoyed at questions that they think are "dumb", but my opinion is don't worry. If you have a question and are curious about it, that is what a forum is for. So, I say, don't worry if you think the question is "dumb". Just ask away.
Now, to the question, as mentioned by AFC_ajaz00, Anchorage is a very convenient fueling stop. Often, the weight of the cargo is much higher than the weight of say passengers (obvious differences such as flowers and textiles, versus some heavier machinery, etc.) Anyway, the aircraft could operate a segment, say New York - Hong Kong nonstop, but weight from fuel would account for a significant proportion of the MTOW (max. take off weight), and the airline would have to limit the amount of cargo that it can carry (again, the density of the cargo plays a role). This is the same for passenger flights on extreme long haul flights. Because the amount of cargo carried is what determines revenue, most airlines would rather fly a fully loaded aircraft and make a stop in say Anchorage to refuel. The cost of landing, refueling, and taking off again is generally more than made up for in the additional revenue from operating a full flight.
Another benefit to some carriers is the ability to use Anchorage as a sorting hub for flights in each direction. Fed Ex, UPS, and Northwest all have large facilities up there for doing this. This similar to a hub facility for passengers and imrpoves efficiency. To my knowledge, the Asian airlines tend to just land, refuel, and take off. They generally only operate from one city at one end (i.e. Cathay Pacific Cargo flights come from only Hong Kong and go to several U.S. cities, hence no need to transfer cargo. Northwest flights come from several U.S. cities and go to several Asian cities, so there is some need to transfer cargo). At the moment, I don't know of any Asian airlines that transfer cargo in ANC
. When I was there, they just pulled up and parked in the space between the two terminals, refueled, changed crews, and were off again. It is quite impressive if you can hit a busy time for them. Quite a few 744Fs of the Asian cargo carriers there and up close to see.