In English law, the term Counsel is a reference to a Barrister-at-law, and can mean either a single person who pleads a cause, or collectively, the body of barristers engaged in a legal case.
However while a ‘Barrister’ is a professional title awarded by one of the four Inns of Court, ‘Counsel’ is used to refer to a barrister who is instructed on a particular case.
In the US, the term counselor-at-law designates, specifically, an attorney admitted to practice in all courts of law, and most US citizens use the term loosely in the same sense as lawyer, meaning one who is practicing in law.