Publicity is gaining public visibility or awareness for a product, service or your company via the media. It is the publicist that carries out publicity, while PR is the strategic management function that helps an organization communicate, establish and maintain communication with the public. This can be done internally, without the use of media.But Advertising is the communication relayed from companies to persuade an audience to purchase their products. This communication is usually through various forms of paid media -- TV and radio commercials, print ads, billboards and more recently, product placement.