Advice is a recommendation or opinion that is offered to another as a guide to action, conduct or behavior. It may also refer to a communication, usually from afar, that contains news or information.
In commerce an advice may be an official notification pertaining to a business transaction or demand for payment while in legal matters advice is the giving of a formal and binding opinion regarding the substance or procedure of the law.
Someone who gives advice is referred to as an adviser or advisor. Often used in the field of policy, law or financial matters.