What's in a character?

There are many guides on how to write believable characters, or lovable ones, or relatable ones, and any other adjective under the Sun... but what is, really, a character? When does an arbitrary set of lines and dialogue stop being mere words to become something we can see as a person?

This 12 pages long zine aims to explain how I personally define a "character," and what it means when it comes to creating and analyzing them.