The terms in your filename typically provide technical context used by fansubbing or encoding groups: Refers to the episode number.
Often indicates a "Professional" or "Premium" encode, sometimes associated with specific release groups that prioritize high-bitrate video. Edens_Zero_21_Pro_ACB.mkv
Likely a shorthand for the release group's name or a specific audio/video codec configuration used for that file. The terms in your filename typically provide technical
This episode concludes a major portion of the with the following key events: Edens_Zero_21_Pro_ACB.mkv