Unless you can name all the parts of a standard banjo, now is the time to check out Anatomy of a Banjo: https://www.deeringbanjos.com/pages/banjo-anatomy#more-info. (I’ll be using these terms pretty often.) I’ll wait while you educate yourself.
If you already play the 5-string banjo (or any fretted instrument), you may be curious to try a capo-ble banjo. First the bad news: nobody that I know of makes them. The good news: you can get around that. There are several ways; I’ll start with the easiest and progress to the hardest.
The easiest way is if you have a guitar (6-string) banjo. Just remove the 6th string, and replace the 1st-5th with 11, 13, 17, 28W, and 9 gauge strings. For 24” length strings you will need to tune to F rather than G: C, A, F, C, F. (If you try to tune higher, you’ll break a string.) (If you play the C tuning, you’ll need to tune the 4th string to Bb)
Next way is on a standard 5-string banjo. Replace the 1-4 strings with 11, 13, 17, and 28W gauge strings. Capo at the same fret as the 5th string, and tune to the key of C: G, E, C, G, C.
Next, you can get your local luthier to make a neck to fit your pot. The fretboard must accommodate a 22” string length for the regular G (or C) tuning.
Finally, you can build your own capo-ble banjo, which is what I did. It’s easier than building a standard 5-string, but only a little easier. I was proud to have completed it, but not proud of its appearance. Someone called it “the ugliest banjo he ever saw.” But he liked playing it.
Capo-ble Banjo 