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.
Type42 was based on the PostScript language for displaying TrueType fonts. It allows for printing all TrueType fonts on PostScript printers and allows for rasterization when displayed. All changes in font structure occur with PostScript procedures. It supports multibyte TrueType fonts in Chinese, Korean and Japanese.