
To clarify, the information I'm about to provide is not my opinion. It comes from Harold L. Peterson, author of American Knives, among many books he authored on the subject of knives and firearms. If you're not familiar with him I encourage you to do a google search on the man. Here's what he has to say on the subject.
First a couple of diagrams from the book to provide definitions: Note the differences in what are called "scales" and "handles" on fixed blades versus pocket knives.
Now let's see what Peterson has to say about this: Hope this is helpful. (Pictures should enlarge by clicking on them).
Ken