They are supported by civil servants who work across devolved areas that include key areas of public life such as health, education and the environment.
Maent yn cael eu cefnogi gan weision sifil sy’n gweithio ar draws meysydd datganoledig sy’n cynnwys meysydd allweddol o fywyd cyhoeddus fel iechyd, addysg a’r amgylchedd.