Transliteration is a conversion in the script. eg:
arabic كتاب = ktʾb (ISO-233)
hebrew זכר = rkzzkr (ISO 259-3)
Transcription is a conversion according to the phonological rules. The IPA is one common target for such conversion:
arabic كتاب = ktaːb (direct transcription, omitting unwritten vowels)
Translation translates text from one language to another
arabic كتاب = book