Advertising is a communication whose purpose is to inform potential customers about products and services and how to obtain and use them. Many advertisements are also designed to generate increased consumption of those products and services through the creation and reinforcement of a company's image and customer loyalty.
Advertising is a single component of the marketing process. It's the part that involves getting the word out concerning your business, product, or the services you are offering. It involves the process of developing strategies such as ad placement, frequency, etc.
Advertising includes the placement of an ad in such mediums as newspapers, direct mail, billboards, television, radio, and of course the Internet. It comprises of both ATL and BTL activities.