Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines for it's targeted keyword) via the "natural" or un-paid ("organic" or "algorithmic") search results. In general, the earlier (or higher ranked on the search results page), and more frequently a site appears in the search results list, the more visitors it will receive from the search engine's users. SEO may target different kinds of search, including image search, local search, video search, academic search, news search and industry-specific vertical search engines. Search engine marketing, (SEM), is a form of Internet marketing that seeks to promote websites by increasing their visibility in search engine result pages (SERPs) through the use of paid placement, contextual advertising, and paid inclusion.
SEM. It's everything that can be done to utilize the technology of search engines with the goal of promoting a web site and increasing its traffic, its "stickiness," and, in the case of sites that promote a business (or are a business), increase profits. SEO, therefore, would be a subset of SEM. No SEM campaign is complete without SEO. Moreover, since the purpose of SEO is to make the site better for both search engines and users, you may find that it will suffice on its own. In any case, the advantages of SEO over the other aspects of SEM make it clear that, even if you are going to spend additional money on advertising and paid placement, SEO must be your first step in promoting your site.
SEO - SEO(Search engine optimization) is a technique which is improve our website ranking, popularity, Visibility, traffics and visitors on the major search engines like Google, Yahoo, Msn etc. These things give us more business. It is free business promote technique. SEM- SEM(Search engine marketing) is a paid website promote technique like PPC, Email Marketing and other
SEO basically stands for Search Engine Optimization. SEO is process of improving the visibility of your site in search engine. SEM stands for Search Engine Marketing. Search engine marketing is a form of Internet marketing to promote websites by increasing their visibility in search engine result pages through the use of paid placement, contextual advertising. SEM gives a huge traffic in a short period of time.