The Flexible Image Transport System (FITS) is an open standard digital file format used primarily in astronomy and other scientific fields for the storage, transmission, and processing of data. Developed in the late 1970s, it is designed specifically to handle multidimensional arrays, such as 2D images or 3D data cubes, and structured data like tables. Unlike standard image formats like JPEG or PNG, FITS files are capable of storing high-precision floating-point data and extensive metadata within human-readable ASCII headers. These headers provide critical context, such as telescope coordinates, exposure times, and instrument settings. FITS is highly extensible, allowing for multiple data extensions within a single file, making it the global standard for astronomical data exchange and archiving by organizations like NASA and the ESA. Its design ensures long-term archival stability, as the format is strictly backward compatible and platform-independent, ensuring that data recorded decades ago can still be read by modern software without loss of information.