Orchestral flute is a woodwind instrument and it is mainly being used for melodic performance. It has a peculiar warm and clean sound with nice colors. In an orchestra the typical number of flutes is two to four, played by the Flutists.
It is a reed less woodwind with a range from C4 to D7. So it is dominating the higher registers of the frequency map. Sometimes we could have flutes that begin from B3 with a B foot. It is the soprano part of woodwinds section. Flute's notation uses the treble clef and it sounds as written. Its dynamics could reach from ppp to ff making it a very expressive instrument. A very important role is its dynamics has the frequency region we play - the higher the register the more difficult to play in lower intensities.
A flute could be constructed with a variety of materials, each of one resulting in different sound characteristics.
Beside being part of an orchestra, we could find the usage of this instruments to a variety of music genres from New Age to Progressive Rock and from Cinematic to Heavy Metal styles.
One of the best examples, at least for my own taste, is Jethro Tull. This great prog rock band relies a lot to Ian Anderson's flute performances.
We could also create some flutish sounds with various synthesis methods in synths. In this way we could never achieve the originality of the flute's sonic blueprint but sometimes a synthetic variant is what a song needs of. My favorite typical OSC shapes for creating flute type synths are sine waves and triangle waves.