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 7-bit font format used for directly downloading to a PostScript printer. It has two character encoding in hexadecimal. It has good compatibility with multiple font formats. PFA contains an outline for font symbols and is formatted in ASCII text data.