Search Engine Marketing and Search Engine Optimization: Is there a difference?

In the simplest way possible, SEM and SEO are tools that website builders, especially those who promote and sell a specific service or product, use in order to get a lot of exposure and better ranking for their website. Seems easy enough, right? Well, the simplicity ends there.
To make it a little more complicated, search engine marketing and search engine optimization are not the same. As suggested by the names, SEM, or Search Engine Marketing, deals more with how you market a website to get exposure in the various search engines available on the Internet, while SEO or Search Engine Optimization deals with how web builders develop and redevelop the entire content, quality, and structure of their websites so that whenever an Internet user types a certain word into a search tab, their websites have a better chance of appearing in the search engine (SER) pages.
Now, to make it more complicated, although SEM and SEO functions look different, they are much more effective when used together. Since the main function of SEM is to get more exposure for a website, the most popular means of attraction are online advertisements, blogs, internet articles, partner sites, sponsored sites, and anything that can catch the eye of an internet user. SEM also uses PPC (Pay Per Click) and paid embedding to increase website visibility. Finally, it is also important in SEM to send the name and URL of a website to different search engines and web directories to inform them that only the website exists. All this is done to ensure the popularity of a website.
So, how does SEO combine with search engine marketing? Well, despite all the ads that SEM provides, it is really the SEO that allows the internet user to easily and conveniently find what they are looking for. Since the job of SEO is to get a better ranking in SERPS, a web builder must constantly improve their website in order to meet the needs of the internet user and make it easier for spiders or web crawlers to judge if the content of a website is relevant to the searched word/s. Optimization is not a simple and easy task. This includes having to regularly restructure the website (by editing the html code and meta tags, changing the content, reorganizing the sitemap, developing an easier navigation structure, etc.) in order to adapt to the rapidly changing demands of the Internet user. However, when done right, SEO not only helps a website become more useful and thus visited more often by an internet user, it also helps gain more exposure as it increases the chances of a website ranking better in SERPS.
The success of both search engine marketing (SEM) and search engine optimization (SEO) depends greatly on the words or context that internet users type in whenever they search for something on the internet. Take PPC within SEM, for example. PPC is an advertisement that is triggered by a specific word or context used by an Internet user. Once you search for a specific word or context, a website pay-per-click ad appears. SEO works the same way. The web builder inserts a specific meta tag (or keyword) in his or her html that he thinks many Internet users will use when searching for information, information that the web builder’s website may contain.
Although all these processes involving search engine marketing and SEO are tedious and time consuming, it all boils down to knowing and serving your target audience. A web builder must be knowledgeable enough to know what the internet users need and want and at the same time he must have the real passion for informing and providing the internet users with the right service and product.