Rosin core vs Silver Bearing?

I have seen people mention rosin core silver bearing as one item. Where as I went to Radio Shack and I saw that there was just either rosin core or the silver bearing. When someone says rosin core silver bearing, are they normally referring to just rosin core or is there a type of solder actually called rosin core silver bearing and then just silver bearing?

Thank you.

I bought the silver bearing stuff at radioshack, and Ive never noticed a problem with it. I dont think it has rosin in it though, because I usually have to use a bit of acid flux to make a good connection. Never heard of Rosin Core Silver Bearing Solder, but Im sure it exists somewhere.

it has rosin core the cat# is 64-013 the full name is High-tech.Rosin-core Silver-Bearing Solder