Each hero has the ability to train in any of 6 available jobs. Heroes may only have 1 job active at any time, but may switch jobs any time they are in the village.
As heroes fight monsters, they will gain experience in whichever job they are fulfilling at the time, so a hero who has been a Knight for a long time will gain levels and skills in that job, but will remain a novice in Wizardry. Switching jobs does not reset experience in old jobs, so heroes can become masters of multiple jobs over time with enough practice.
Heroes may use 1 skill, 1 ability and 1 subjob ability at any given time. Available skills and abilities are dependent on which job is active at the time.
Skills are actions that your hero takes in battle. Abilities are passive benefits that occur automatically when your hero fights. Subjob abilities are additional abilities that your hero gains access to by training in multiple different jobs.