Families of Writing Systems
Another way to classify writing systems is by "family". This is an even looser way of classification because, as in real life, the definition "family" can get fuzzy. Here "family" can denote a group of writing systems that either have evolved from a common ancestor or have similar "style" or appearance. (An example of this latter definition would be Old Persian, which looks like cuneiform but isn't directly descended from Summerian or Akkadian).