Subtitle - A subtitle can refer to one of two things: textual versions of a film or television program's dialogue that appear onscreen, or an explanatory or alternate title, in addition to the main title of a work. In films and television subtitles are textual versions of the dialogue that appear onscreen. They are sometimes added to films when they are released in a country that speaks a different language to that used in the film. They are also used in a variety of other films when some dialogue is spoken in a foreign language; for example, in Star Trek, when the Klingon language is spoken, subtitles are often placed on the screen to enable the viewers to understand what is being said.

Dubbing - The process of recording or replacing voices for a motion picture. The term is most commonly used in reference to voices recorded which do not belong to the original actors and speak in a different language than the actor is speaking, resulting in a mismatch of the words heard by the viewer and the movements of the actor's lips (especially when one acquires both the original and the dubbed version). Dubbing can also be used to describe the process of re-recording lines by the actor who originally spoke them. The process is technically known as automated dialogue replacement, or ADR.

Localization - The process by which multiple language versions of a product are created.

Lip Synch - is the art of making a character appear to speak in a pre-recorded track of dialogue. The lip sync technique to make an animated character appear to speak involves figuring out the timings of the speech (breakdown) as well as the actual animating of the lips/mouth to match the dialogue track.

ADR - Automated dialogue replacement (ADR) is a film sound technique involving the re-recording of dialogue after photography. ADR is recorded during an ADR session. An actor, usually the original actor on set, is called to a sound studio equipped with video playback equipment and sound playback and recording equipment. The actor wears headphones and is shown the film of the line that must be replaced, and often he will be played the production sound recording. The film is then projected several times, and the actor attempts to re-perform the line while watching the image on the screen, while an ADR Recordist records the performances. Several takes are made, and based on the quality of the performance and sync, one is selected and edited by and ADR Editor for use in the film.

Closed Captioning - Closed captioning (CC) allows deaf and hard of hearing / hearing-impaired people, people learning English as an additional language, people first learning how to read, and others to read a transcript of the audio portion of a video, film, or other presentation. As the video plays, text captions are displayed that transcribe, although not always verbatim, what is said and by whom and indicate other relevant sounds.

Translation - Translation is an activity comprising the interpretation of the meaning of a text in one language—the source text—and the production of a new, equivalent text in another language—called the target text, or the translation. The goal of translation is to ensure that the source and the target texts communicate the same message while taking into account the various constraints placed on the translator

Voice-Over - A voice-over is a narration that is played on top of a video segment, usually with the audio for that segment muted or lowered.