one of my TAs just beat me up for not emphasizing some terminology

I thought I had done this, but if my TA says I slipped over it too fast,
then I had better do it again, more carefully.  Ergo, this email.

The index bits take us to a row in the tag store.  We call the set of 
the blocks accessible via the same index bits a "set," and the number of
blocks in the set the "set size."  We call each block in the set a "way."

The number of "ways" in a set identifies an important characteristic of
the cache.  For example, a "four-way set associative cache" is one wherein
four blocks are in the same set.  We do not usually say "one-way" when there
is only one block in the set.  Rather we call such a cache "direct mapped."
If all blocks in the cache are in the same set, we call the cache "fully
associative."  All blocks in a set compete for the same slots in the cache.

If I did not emphasize this terminology, I should have.  Everyone is going
to expect you to know these terms.

Yale Patt