For many casual internet users, the terms SEM and SEO rarely enter their minds when they are busy jumping from one website to another. However, it is these terms that determine much of what comes out on the results page whenever we type in a word in the search tab of any accessible search engine. These terms are also responsible for all those advertisements and pop-ups that link us to even more websites, whether they may be connected to our original search or not. So just what are SEM and SEO?

In the simplest way possible, SEM and SEO are tools which website creators, especially those who are promoting and selling a certain service or product, use in order to gain a lot of exposure and better ranking for their website. Sounds easy enough, right? Well, the simplicity ends there.

To make it a tad bit complex, SEM and SEO are not the same. As suggested by the names, SEM, or Search Engine Marketing, deals more with how a website is marketed to gain exposure in the different search engines available on the internet, while SEO, or Search Engine Optimization, deals with how the web creators develop and re-develop the content, quality and structure of their entire websites so that whenever an internet user types in a particular word in the search tab, their websites have a better chance of appearing on the first few search engine results pages (SERPS).

Now, to make it even more complex, although the functions of SEM and SEO seem different, they are more effective when used together. Since the main function of SEM is to gain more exposure for a website, the more common means for attraction are online advertisements, blogs, internet articles, partner and sponsored websites, and anything that can catch the eye of the internet user. SEM also makes use of PPC (pay-per-click) and paid inclusion to further push a website's visibility. Lastly, it is also an important process in SEM to submit the name and URL of a website to different search engines and web directories if only to inform them of the website's existence. All this is carried out to ensure the popularity of a website.

So how does SEO come together with SEM? Well, despite having all the advertisements provided by SEM, it is truly the SEO that allows the internet user to easily and conveniently find what he is looking for. Since the function of SEO is to gain a better ranking in the SERPS, the web creator has to constantly optimize his website in order to cater to the needs of the internet user and to make it easier for spiders or web crawlers to judge whether the website's content is relevant to the word/s being searched. Optimization is not a simple and easy task. It involves having to restructure the website regularly (by editing the html code and meta tags, changing content, reorganizing the site map, developing an easier navigational structure, etc.) so as to adapt to the rapidly changing demands of the internet user. Still, when done properly, not only does SEO help a website become more useful and therefore, more often visited by the internet user, it also helps gain more exposure since it increases the website's chances of gaining a better rank in the SERPS.

Both SEM and SEO success rely heavily on the words or context which Internet users type in whenever they search for something on the internet. Take PPC under SEM, for example. PPC is an ad that is triggered by a particular word or context used by an internet user. Once a particular word or context is searched, a corresponding PPC ad for a website comes out. SEO works in the same way. The web creator inputs a particular Meta tag (or keyword) in his html that he believes many internet users will use when searching for information, information which the web creator's website may contain.

Although all of these processes involving SEM and SEO are tedious and time-consuming, it all boils down to knowing and serving the target audience. A web creator must be discerning enough to know what the internet users need and want, and at the same time he must have the real passion to inform and provide the internet users with the right service and product.