Flutes, like clarinets are woodwind instruments. This means that they function by blowing air through them to make a tone. However, the obvious difference is the fact that the flute is played to the side while the clarinet is held vertically. It should also be noted that a clarinet requires the use of a reed, while a flute is the only woodwind instrument to not require one.
Aside from these differences, the flute and the clarinet break down into a different number of pieces—a flute has 3 pieces, whereas a clarinet has 4 pieces. The tone in the instruments is also different, a flute is generally higher-pitched and a clarinet can play much lower notes.
The main difference between a clarinet and a flute is the presence and absence of reeds. Flutes are reedless instruments, whereas clarinets have a single reed. The clarinet is an end-blown instrument whereas flutes are side-blown instruments. The clarinet has a barrel. The barrel is used for toning, and it comes in a variety of sizes.
The flute doesn't have a barrel. It has a head joint cork used for tuning the instrument. The flute has a middle piece, which is the body of the instrument. The clarinet has two middle pieces. The flute has a foot joint that only consists of three keys. The clarinet, in contrast, has a bell at the end of it that is used for tuning purposes.