Do you ever wonder what to call these things?
They are some of my favorite writing instruments and are actually composed of these pointy metal things which are called nibs. Nibs come in lots of different sizes. They also vary in the level of flexibility. When you find a nib you love, you might buy a bunch of them like I do. The best way to get to know about nibs is to try them out. They don't cost very much so I say get to know as many as you want.
I suppose you could hold a nib with your fingers to write with but that would be inconvenient and so you usually put them in these longer objects called nib holders. Nib holders also come in lots of sizes and thicknesses and colors. They're a bit more pricey than nibs so you probably won't buy as many nib holders than you would buy nibs. But the best way to learn about nib holders is to try them out. (Note: The two that look really weird like the second from the left and the one on the right are called oblique holders. "Oblique" means slanting. Makes sense, right? No need to be afraid of oblique holders. They are one of my favorites to work with.)
So then you push the nib into whiever holder you want to use. There's really no wrong way to do this. Just shove it in there so that it's nice and tight. The holder's job is to keep the nib nice and steady so you can write with it. If you decide you want to put a different nib in the holder, just pull it out and put a different one in. Usually, most nibs will fit in most holders so don't worry too much about potential mistakes. If a nib for some reason doesn't fit into a holder, then don't put that nib in that holder. Simple as that.
After you have the nib in a holder, you dip it in some ink. Some folks recommend that you put a new nib to a flame for a few seconds or to dip a new nib first into gum arabic to help break it in. I've done that before and sometimes I've not done that. Whatever. And becasue you dip the nib into ink, that's why you call these nibs with holders "dip pens." People also just call them calligraphy pens ... which is a bit more of a general term which could mean other things.
Once you dip it, you'll see that a bit of ink gets captured in the nib. Not a lot. Just a little bit. This shot below shows the nib's concave side, where you can see the captured ink.
Enough to write a letter or a word or even a couple of words. Depending on how much a nib captures, you'll have to redip to get more ink on the nib to finish what you are writing. (Note: Isn't that thick nib at the top cool? I think it's rad. It was given to me by Lisa Engelbrecht. Thanks, Lisa!)
Here are some pens with calligraphy-type nibs that you don't dip into ink. The nibs also don't get removed. Usually. Rather, they come with ink cartridges that you replace now and again. I personally call these "calligraphy ink cartridge pens." They're convenient when you don't have the wherewithall to take ink to wherever you are going.
The one thing I've learned about nibs and nib holders and such is that owning every variety available is not what will make your lettering awesome. Practicing and experimenting is what will make it awesome.