I am a P. Eng. in Ontario, Canada. It's "Professional Engineer" license. As someone else has mentioned, you can be a mechanical engineer, a software engineer, an electrical engineer etc and a P. Eng. The requirement for P. Eng is passing an Engineering Ethics exam, receiving an engineering degree from accepted universities/college (doesn't have to be a Canadian school) and completing an certain number of years of Canadian engineering work experience (ie. the work must be qualified as engineering type work, and must be in Canada). Now, I received my P. Eng more than a decade ago so the rules may or may not change.

Professional Engineers of Ontario (PEO) is our organization which regulates the exams and licensing. It is also a sort of watch dog which ensures that engineers are ethical and don't cut corners. PEO also provides networking (they may organize a plant tour or conferences etc) and volunteering activities for engineers. We, engineers, pay annual fees/dues to PEO but if you work for an engineering company, your company may pay your dues for you.