Tag Image File Format

Tag(ged) Image File Format (TIFF) is a file format used for still-image bitmaps, stored in tagged fields. Application programs can use the tags to accept or ignore fields, depending on their capabilities.

History
While TIFF was designed to be extensible, it lacked a core of useful functionality, so that most useful functions (e.g. lossless 24-bit color) required nonstandard, often redundant, extensions. The incompatibility of extensions has led some to derisively expand "TIFF" as "Thousands of Incompatible File Formats".