Professions are jobs that people have. Like doctors, for example. There are different kinds of doctors. If someone has a sickness, doesn't have to be a specific one, they come to a doctor. Another profession is a business man. There are loads of different ones. Some have a website of their own, some have ads all over the internet. Most of the time, they make lots of money and have other people recruited for the job.
Glad to help :)
I know all of this because I'm from England myself. I moved to Moscow 2 years ago and learned Russian, so I'm on this website now haha.