A subset of SEM is SEO. A subset of SEM is PPC. A subset of SEM is Link Development. A subset of SEM is SMO (facebook ..etc..). A subset of SEM is traditional adverts. A subset of SEM is Paid inclusion. Search Engine Marketing SEM covers all of these areas. To truely develop website potential all these areas (SEM) must be covered
SEO :-> Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. SEM :-> Search engine marketing, or 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.[1][2] SEM is NOT SEO and vice versa. SMO :-> Social Media Optimization (SMO) or Social SEO is the methodization of social media activity with the intent of attracting unique visitors to website content. SMO is one of two online methods of website optimization; the other method is search engine optimization or SEO.