Transliteration is a conversion in the script.
eg:

arabic كتاب  = ktʾb (ISO-233)

hebrew זכר = zkr (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