Here's a great question from reader Wyatt, who is struggling to identify all the knives in his new set. He writes:
I received a butcher block and some decent knives for Christmas, and it's nice to have a full fresh set with all the amenities. However, I keep finding that I really only end up using the large chef's knife, the short paring knife, and the bread knife. I've missed some crucial aspect of my education, I think: what are the rest of these for?
What makes a fillet knife a fillet knife, and what characteristic would make me want to choose it over one of my standbys? And the rest of these, too! I haven't the foggiest idea what to call them, let alone what makes them useful. Please, Kitchn, tell me about knives!
Wyatt, congrats on your big new set of knives! We are just like you, though: we use a chef's knife (several, actually), a couple of crazy-sharp paring knives, and a bread knife. You've stumbled on the exact reason why we don't usually recommend that cooks buy full sets of knives. We think that many of these knives are not used frequently enough to warrant a place in the kitchen, and that most of their functions can be accomplished just as well with a good chef's knife.
But now that you do have a full set, you might as well take advantage of them! You didn't specify the exact set of knives, but here are some knives common in these box sets.
8-inch and 6-inch chef's knives: Knife sets sometimes include multiple sizes of chef's knife. It's nice to have more than one chef's knife handy, but we prefer to just buy two knives that we really like.
Tomato knife: A tomato knife is serrated, sometimes with a forked end, which lets it cut easily through tomatoes.
Boning or fillet knives: Boning and fillet knives are related and quite similar. They both are thin and flexible, which help them slice bones away from meat. Fillet knives are most frequently used to remove bones from fish.
Bread knife: A long, serrated knife that is ideal for cutting bread. Even this is a one-use knife, we cut bread almost every day and find it very handy.
Paring and utilty knives, in various sizes: Many sets throw in a few short paring knives or utility knives, somewhere between the size of a paring knife and a chef's knife. These can be used for peeling, cutting up vegetables, or any other small tasks.
Santoku: Some new sets are including santoku knives, which are great for slicing and chopping. You can see more about santoku knives here.
Steak knives: Sometimes serrated steak knives are included with a knife set. These are used at individual place settings when eating large cuts of meat: steak, pork chops, lamb chops. We don't use these at all; usually when we serve steak we cut it into more manageable thin strips.
Any more advice for Wyatt? Here are a few more posts, too, with some advice on knives.
• Good Question: What Is the Best Chef's Knife?
• 2005 Holiday Gift Guide: Knives!
• Good Product: Victorinox 8-inch Chef's Knife
• Cook's Illustrated Guide to Kitchen Knives
(Pictured above: Cuisinart 21-Piece Knife Set with Block and Bonus Poly Cutting Board)
Straw Mat from The ...

Show. All of these knives are for show. ;)
I am finally getting rid of the knife block and putting in a magnetic strip for the few knives I actually use - the rest I'm either sticking in a drawer or just giving to a friend.
I use my santuko knife most of all.
Then the small paring knife.
Then the bread knife, which I also use for cutting tomatos.
And that's it, really. The large chef's knife I use when my santuko is dirty :)
HA! This is exactly the set I have (except mine is black). I use all of them regularly except the steak knives...Big santoku, Little santoku, chef...paring...bread...short serrated....LOVE them all.
I've found that for my tiny kitchen I prefer to use a 6" chef's knife for most things. Were I not confined by space I might go back to using the 8" more often, though to be honest I like the finer control I have with the 6". Still, those two knives along with a small paring knife are the ones I go to most often. There are times I go for my santoku knives, but those times are rare nowadays. If I needed to cut tomatoes I'd use my bread knife, but I'm cheap and lazy and go for canned. Sorry folks.
We actually just had to revert from the magnetic strip to a knife block due to the set up of our new kitchen. tear.
We use a bread knife (it's about 7" so I'll use it on beefsteak tomatoes, too) a santoku, a shun chef's knife, and paring knives. If I'm cutting roma tomatoes I just use on of the enormous steak knives that my husband got for Christmas a few years ago.
I can see using all of these knives if you're a serious cook, but not if you're just whipping up basic meals.
One day, I'll have the in-counter knife storage that Alton Brown has. It makes me drool every time I see him use it.
http://embritadesign.blogspot.com
I use my 6" chef's knife most of all, then my 8" and bread knives. Oddly enough, I very rarely use my paring knife. Fortunately, my knife block only came with the 6", 8," and paring knives, a steel and a pair of kitchen scissors so there's not much extranious stuff in my set. I should probably switch to magnetic storage, though. Counterspace is at a premium.
They're for learning to throw knives at a target so you can join the circus.
Seriously, you've already found almost all the knives you need. We have 5 knives, which is more than enough for my sweetie and me to cook anything we please: a chef's knife, a slicer (almost as long, but more slender than chef knife), 2 paring knives, a bread knife, and a fillet knife (this last rarely gets used).
the only reason I sometimes wish I had more knives is if I haven't planned out my cooking well and have to cut up more veggies or cooked foods after I cut up raw meat. Otherwise I just use a 6 (or is it 7) inch chef's knife, a paring knife, and a serated knifed I stole from the flatware set (for tomatoes, bread, whatever needs seration).
Woah, thanks for all the advice, everyone. That was actually quite informative and to-the-point. I appreciate it-- if nothing else, contending with bones just got a whole lot easier. :)
-The not-quite-eponymous Wyatt