A TIE Fighter was the starfighter of the Galactic Empire. They were small and fast and inexpensive to produce. As most starpilots new, for every TIE that was shot down, a thousand would take its place.
Although the fighter was shapped like a tie, its name stood for Twin Ion Engine. The TIE was created after the reformation of the Galactic Republic into the Galactic Empire. Twin Ion Enginge technology first created the Sith Infiltrator, and the TIE fighter's design was based after the Infiltrator.
The TIE was equipped only with two laser canons. It only had one pilot, no passengers, and was deprived of hyperdrive, deflector shields, life-Support systems, and langing gear. The pilot had to wear a space-suit. The lack of shield protection was part of the Empire's belief that each fighter and each pilot was expendable. The money not going to shield protection went to the production of even more TIE fighters.
The TIE was such a great fighter, it inspired the ideas for many variants of the TIE fighter, for almost all climates and purposes.
See TIE Variants.