13.2. Font Types.   

There are 2 major sorts of fonts : Bitmapped fonts and Outlined (Scalable) fonts. Outlined fonts are also known as Vector fonts. Bitmapped fonts are fast falling out of fashion as various outline technologies grow in popularity and support.

Bitmapped Fonts
Bitmapped Fonts represent each character as a rectanglular grid of pixels. The bitmap for each character indicates precisely what pixels should be on and off. Printing a bitmapped character is simply a matter of sending the right bits out to the printer. There are a number of disadvantages to this approach. The bitmap represents a particular instance of the character at a particular size and resolution. It is very difficult to change the size, shape, or resolution of a bitmapped character without significant loss of quality in the image. On the other hand, it's easy to do things like shading and filling with bitmapped characters.
Outlined Fonts (Vector/Scalable Fonts)
Outlined fonts represent each character mathematically as a series of lines, curves, and 'hints'. When a character from an outlined font is to be printed it may be 'rasterized' into a bitmap "on the fly". PostScript printers, for example, do this in the print engine. If the "engine" in the output device cannot do the rasterizing, some front end has to do it first. Many of the disadvantages that are inherent in the bitmapped format are not present in outlined fonts at all. Because an outline font is represented mathematically it can be drawn at any reasonable size. At small sizes, the font renderer is guided by the 'hints' in the font; at very small sizes, particularly on low-resolution output devices such as screens, automatically scaled fonts become unreadable and hand-tuned bitmaps are a better choice(if they are available). Additionally, because it rasterized 'on demand', the font can be adjusted for different resolutions and 'aspect ratios'.

There are many types of fonts around. Here are some of the type of fonts that are commonly used.

TrueType font is categorized as an outline font concept. It was first developed by Apple Computer, Inc in 1991 and later introduced by Microsoft. Currently it is used as the standard font format on Microsoft platforms and its applications. The TrueType font was originally designed to meet the 'What You See Is What You Get' or WYSIWYG requirement. Therefore it gives the user great visual help in preparing their documents or works in Windows environment (and other platforms that utilized it). The suffix for TrueType is ttf, for example, myfile.ttf .
PostScript was invented by John Warnock and Charles Geschke from Adobe Systems. It is a page description language (PDL) which is an interpreted programming language to describe text, graphical shapes and images. A PostScript font is categorized as outline font, and therefore able to produce good quality text and images on virtually any size. The suffix for PostScript font is usually .ps . Some Laser Printers provide PostScript facility. If the user doesn't have PostScript printer, there are utilities to print it using non-PostScript printer via ghostscript or ghostview program.
Most Unix tools expect to get character metric information from AFM files. You may have difficulty using fonts collected off the 'Net if they did not include AFM files.
MetaFont is a programming language for describing fonts. It was invented by Donald Knuth. This programming language would produce raster font when specified to display certain kind of font.
Bitmap font
Bitmap font contains a pattern of dots that display the character set it represents. Usually it has the suffix .fnt

Other example of fonts.
Fig. 13.2 : Other example of fonts.