1. Direct characterization. What the character actually does and says in the source material. If the medium allows for it, anything the character is directly shown as thinking. Generally considered the most reliable information. Motivation for the actions may be in dispute, but the character did or said it, so we have to take those events into account.
2. Narrator characterization. What the third person "omniscient" narrator tells us about the character. This is usually a reliable guide as to how the author wants us to think of the character. However, especially in the hands of less skilled writers, or those with axes to grind, it may conflict badly with type 1.
3. "Hearsay" characterization. What other characters in the source material say about the character, and how they react to her actions. This may say more about the other characters than the focus one, but is a good guide as to how the character is perceived in their own milieu as opposed to the reader's society.
4. "Default" characterization. Subjects that never come up in the actual source material, but can be logically presumed. For example, many fictional works do not bother to mention their female characters having periods, but based on real-life experience, most female characters would at some point have them.
Other categories that can be useful?