Internet marketing, also known as digital marketing, web marketing, online marketing, search marketing or e-marketing, is the marketing (generally promotion) of products or services over the Internet. Search engine optimization (SEO) is a set of methods aimed at improving the ranking of a website in search engine listings.Generally speaking, advertising is the promotion of goods, services, companies and ideas, usually by an identified sponsor. Marketers see advertising as part of an overall promotional strategy.Other components of the promotional mix include publicity, public relations, personal selling and sales promotion.Online advertising is advertising on the Internet. This particular form of advertising is a source of revenue for an increasing number of websites and companies.