CC1101, NRF905, PTR8000+, difference between modules (?)

I'm looking into wireless transceivers and some of the names confuse me. As far as I can tell NRF's are made by Nordic, CC1101's are made by Texas Instruments. However I find on ebay:

CC1101, but also named NRF905, is it because they are interchangeable?

CC1101, by itself

NRF905, but also called PTR8000+, no idea what that means

I'm not really sure whether all three are different, or two are basically the same. Your input is appreciated.