Phonetics (pronounced /fəˈnɛtɪks/) is the branch of linguistics that studies the sounds of human speech, or—in the case of sign languages—the equivalent aspects of sign. It is concerned with the physical properties of speech sounds or signs (phones): their physiological production, acoustic properties, auditory perception, and neurophysiological status. Phonology, on the other hand, is concerned with the abstract, grammatical characterization of systems of sounds or signs.
From that I guess you can infer the difference, although you probably should be aware that if "phonologist" and "phonetician" really exist as words, they are very specialised, if not jargon terms. I have never heard or read either of them before.