Just a quick question:
Is a suffix tree (a tree that stores suffixes of words) a type of b-tree please?
No, the two are not really the same. Some B trees are vaguely similar to a suffix tree in storing only enough of a key for uniqueness. Other than that, however, there's almost no resemblance between the two at all. In particular, a B tree is defined largely in terms of balancing the tree, which isn't normally used with a suffix tree at all.