- character and persona -

Persona is an Italian word that derives from the Latin for a kind of mask made to resonate with the voice of the actor (per sonare meaning "to sound through"). The Latin word probably derived from the Etruscan word "phersu", with the same meaning, and that from the Greek "πρόσωπον". Its meaning in the latter Roman period changed to indicate a "character" of a theatrical performance.

However, there is difference between character, personality and behavior.

1. Behavior is the external appearance without being confirmed or supported by the mind and feelings. 

2. Character is what is supported by the mind and feelings. It is a behavior which is endorsed and directed by the mind. 

3. Personality is on its own. It is self-directed.

Since character is something that is built over time and subjected to changes, unlike personality, which always stays the same, term character is more useful in film theory, being a time based art. Every character must develop or change throughout film, with no exceptions.