Typography is the visual component of the written word. It is the style and appearance of the words. It is also an art and technique to make words readable, legible, meaningful and attractive.
A lot of people confuse typography with computer fonts. Although a font is a large part of typography, it is not the only component. Other considerations include the weight (thickness of the letters), the spacing between letters (kerning), the spacing between lines (leading), and the overall layout and arrangement of the entire text.
Typography can tell a story. Different typefaces (fonts) have history, and evoke different emotions, values and memories in people. A designer must carefully balance the aesthetics and feelings communcated by a choice of font with the functional aspects in order to achieve meaningful and effective communciation.
Bad typography has consequences - from harmless hilarity to serious, or even fatal results. Consider these scenarios:
When done well, good typography is often not noticible to laymen as it is working as intended. Bad typography, however, often stands out. The next time you find something confusing or hard to read, pause and try to notice the font used.