Search engine optimization, otherwise called SEO, is a set of techniques and strategies to promote a web site in search engines for the purpose of increasing traffic and improving its placement in search results pages. Search engine marketing, on the other hand, is an entirely different form of Internet advertising that entails the marketing of web sites by increasing their visibility not only in search engine results Pages, but also in sponsored listings on search pages. This is achieved by paying search engines to place your web site in their search results Pages.
There are basically two kinds of search engine marketing: free and paid. In free search engine marketing methods, you focus mainly on making your website visible so that it can attract a substantial number of visitors; you do this by paying search engines to place your site in their results pages. Paid advertising, on the other hand, places ads on search engine results pages as a means of attracting new visitors to your web site; however, you do not incur any costs in doing this.
The success or failure of any search engine marketing campaign largely depends on the way in which it is advertised. If you use search engine marketing techniques that rely mainly on pay per click campaigns, you stand a good chance of having successful campaigns if someone clicks on your advertisements. On the other hand, if your campaign relies on word of mouth advertising, then it might take some time before your advertisements start appearing on the search engine results page.