File format called FITS is known as Flexible Image Transport System. It is digital format serving to save, transfer and edit scientific and other pictures. Its biggest use is in astronomy and unlike other formats it is targeted especially for photometric and scientific data.
Format was released on June, 1981. Since that it was many times updated and remaked, which leads to his newest version known as v3.0. Latest version that is v3.0 was released on June, 2008. Motto of this file format was: „once FITS, always SITS”, which is similar to: “If it FITS, it SITS”. In practice it meant that it was backward compatible. One of the main advantages is that is compatible with its older versions. He also saves a lot of important data, like spectrum of colors or multi-table databases. It also can save x-ray pictures and infrared variants of certain file.
To open files saved in this file type you can use program FITS Liberator.