Subtitles are textual versions of the dialog in films and television programs, usually displayed at the bottom of the screen. They can either be a form of written translation of a dialog in a foreign language, or a written rendering of the dialog in the same language, with or without added wikipedia.org

Translation from English to Spanish and Spanish to English.

Translation from English to Spanish and Spanish to English.

Proofreading (also proof-reading) is the reading of a galley proof or computer monitor to detect and correct production-errors of text or art. Proofreaders are expected to be consistently accurate by default because they occupy the last stage of typographic production before publication. wikipedia.org

Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. wikipedia.org

Technical translation is a type of specialized translation involving the translation of documents produced by technical writers, or more specifically, texts which relate to technological subject areas or texts which deal with the practical application of scientific and technological information.