SEO (Search Engine Optimization) vs SEM(Search Engine Marketing)
SEO (Search Engine Optimization) is the process of improving the volume or quality of traffic to a web site from search engines via "natural" or un-paid ("organic" or "algorithmic") search results as opposed to search engine marketing (SEM) which deals with paid inclusion. Typically, the earlier (or higher) a site appears in the search results list, the more visitors it will receive from the search engine. SEO may target different kinds of search, including image search, local search, video search and industry-specific vertical search engines. This gives a website web presence.
SEO is definitely an art form in a way and so many designers and devlopers overlook this when they are creating a website because either of the lack of time or mainly due to the lack of knowledge.