An occupation is the principal activity one engages to earn money. A profession is an occupation requiring special knowledge or skill. At the time writing this, historic trades are not an official occupation. For example, a carpenter has a job code on the Occupation Information Network, O*NET: 47-2031.00 – Carpenters. It explains what a carpenter does, their knowledge, skills, and abilities, as well as employment data, like wages and job prospects.