The term "flute" is often used for a wind instrument in general.
We summarize all recorder-like flutes here, i.e. flutes that are blown like a recorder.
The mouthpiece of this flute is built as a core gap flute, which means you have a wind tunnel that is formed by the peg in the top of the flute. The wind tunnel directs the air blown in to a labium, a sharp edge on a window, so that the air breaks there and a sound is created. Recorders are quite easy to blow and are therefore often used as an introduction to the world of wind instruments.
Of course, the classic recorders are known, such as the soprano recorder, which is usually used as the first school recorder. But many traditional flutes are also built as recorders, whether from simple reeds or from sheet metal like the Irish Tin Whistle. The ocarina as a vessel flute is just as much a part of the recorder as the bone flute, the native Indian flute or the one-handed flute like the tabor pipe. Even the overtone flute, which has no finger holes, is blown like a recorder.
What goes beyond that are the travers flute or notch flutes. These flutes have simpler mouthpieces and are blown differently accordingly.