"Typography" is the Art & Science about writing characters, and specially for Graphic Design and/or computers. That means a very wide of answers. First of all, typography can be done by hand, as it was traced for years, it's not only a digital concept. The "digital typography" are computer files for show different kind and size of fonts on each computer. In other words, the "typogrphic families" such as Garamond, Helvetica, Futura, etc were created manually, then translated to metallic frames, and only since a few years translated to compuer language.