Type of files with TIFF extension are graphical files that are using raster graphics. Its whole name is Tag Image File Format, or if you want Tagged Image File Format. Its creator is company known as Aldus that lapsed in 1994. To its advantage belong multipage picture saving that can do only a few formats. This is used commonly in scan devices and faxes.
This format was released in 1986 and since that it has been updated for 6 times. The latest version was created in 1992 and since that it hasn´t get any update. Original version was only for testing. That means that companies wanted to use it as standard for desktop scanners. To this is related fact that it originally used only black and white colors. Later on were added shades of grey. Then it got update that allowed him to use classical colors, which allows him to rival formats as PNG or JPG.
Format TIFF can be opened by many programs. First of all there is classical Picture Viewer in Windows. That can only view these files. Edit can be done in casual Paint program, it is also inside Windows. In addition to these there are two best known applications able to open and edit these files. It is GIMP and Adobe Photoshop with GIMP being free.