A popular form of Internet marketing, search engine marketing (or SEM) is carried out by many businesses to improve the visibility of their website in search engine rankings. There are a number of techniques that fall under the term search engine marketing; as something of an umbrella term, it can cover pay per click (or PPC) marketing and search engine optimisation too. Ultimately both of these techniques - which themselves are considered to be Internet marketing forms - are carried out with the main aim of increasing overall web traffic.
During the mid-nineties search engines really began to gain in popularity; more and more people began to utilise them to find the exact information they were looking for. Search engines recognised this and developed and introduced pay per click adverts. This particular technique allows businesses to tailor adverts, featuring the keywords they rank for, and have them appear on an SERP (search engine results page) whenever the relevant term or phrase is searched. They only pay for the adverts when they're clicked too - hence the name.
Other search engines, such as Google via its AdWords program, followed suit; now a multi-billion dollar industry, search engine marketing is something many companies actively carry out on a regular basis.
Search engine optimisation, as previously mentioned, is another form of Internet marketing that also falls under the term search engine marketing. Businesses, using extensive keyword research, will optimise their sites to feature content rich in the relevant keywords. These sites are then indexed in a search engine and their ranking determined by crawlers.
Crawlers from all of the major search engines will "crawl" through all the content featured on a page. Those website that feature content rich in a certain keyword will rank more prominently either when that keyword is searched or when a similar phrase is searched.
In this form of Internet marketing, there are a number of great methods that advertisers employ to optimise websites.
The most popular one is keyword research and analysis.
Keyword research and analysis will typically involve a total of three steps. The first of these steps is a preparatory measure and involves ensuring that the site to be optimised can actually be indexed. The second is a research phase and involves locating the most popular keywords used by searchers to find the site in question. In the last step all of the keywords found during the second step have to be adopted on the site - in order to help drive traffic levels up.
A relatively straight-forward Internet marketing technique for one to carry out - with the right tools - keyword research and analysis can really help to improve traffic levels by a significant amount. As the terms used by searchers change on such a regular basis, search engine optimisation in search engine marketing has to be carried out on an on-going basis. This Internet marketing technique isn't something that can be carried out for a month and then dropped, or at least not without rankings and traffic levels dropping too.

Search engine marketing is an Internet marketing form employed by many advertisers. This article explains what search engine marketing is.