We try to tag our download files in the most intuitive and consistent way possible. However, many people have their own preferred method of tagging their music so as to navigate their collection as easily as possible, and our method may not be the same as yours!
Fortunately, if you'd like to re-tag your downloaded files to bring the metadata in line with your preferred labelling method, there are many programs available that will do this. MP3tag is one - despite the name, it can re-tag both MP3s and FLACs, though it is not free software. Alternatively, many free-to-download music playing programs (for instance Winamp and FooBar2000) can edit tags as well.