This format was developed to simplify use of Type1-fonts in some software. It’s 8-bit and so it’s quickly processed by programs and it has a compact structure. PFB contains additional metadata. Besides the storage of system fonts, a good example of its use is its application in AutoCAD to create font files with compilation.
This is a standard TrueType font format developed by Apple Computer in 1989. The advantage of TTF till now has been its high level of font display control right up to the pixel. It has a vector format so it’s easy to scale. Today TrueType is used in operating systems from Apple to Microsoft.