Audacity is a free software, cross-platform digital audio editor and recording application. It is available for Windows, Mac-OS-X, Linux and BSD. wikipedia.org

Audio post production is the general term for all stages of production happening between the actual recording in a studio and the completion of a master recording. It involves, sound design, sound editing, audio mixing, and the addition of effects. wikipedia.org

Audio editing is the process of taking recorded sound and changing it directly on the recording medium (analog) or in RAM (digital). wikipedia.org

English is a West Germanic language that was first spoken in early medieval England and is now a global lingua franca. wikipedia.org

"Narration is the act of telling a story, usually in some kind of chronological order."

Voice-over is a production technique where a voice, that is not part of the narrative (non-diegetic), is used in a radio, television production, filmmaking or other medium.

Voice acting is the art of providing voices for animated characters (including those in feature films, television programs, animated short films, and video games) and radio and audio dramas and comedy, as well as doing voice-overs in radio and television commercials, audio dramas, dubbed foreign