SEO vs SEM: What's the difference?

Search engine optimization (SEO) and search engine marketing (SEM) are closely related, commonly confused concepts related to how your website and content are found online. 

SEO is a specific tactic, wherein you optimize your website and online content to increase your rankings in search engine results. (Also, digital marketers just love declaring SEO dead every time Google changes something. Because we're big ol' drama queens.)

SEM refers more broadly to marketing strategies centered around increasing search engine results — SEO can sometimes even be considered an SEM tactic. 

Common SEO activities and tactics

There is no single strategy or tactic that will enable you to optimize your website for search engines. In fact, you may not realize that many of the most common digital marketing strategies are deeply rooted in SEO, including:

Keyword research

Even when you embrace concepts like The Big 5 (the five blog topic categories proven to drive traffic, leads, and sales), keyword research will always play a big role in developing a robust content strategy that increases search engine visibility. For example, as our content director, I will use keyword research to optimize a topic for rankings retroactively and to proactively mine for content ideas, based on what SEMrush (and other content marketing tools) tells me folks are actually searching for.

Topic clusters and pillar pages

In the past five years or so, humans have started talking to their various search-enabled robots (Google.com, smart speakers, and other various Skynet-esque devices) in a way that's more conversational and complex.

As a result, search engines like Google have made drastic changes over the years to better understand the context and intent behind searches, so as to serve up more relevant results.

This change has now forced marketers to reimagine how they architect their content strategies — and thus, topic clusters and pillar pages were born as a way to increase search engine visibility and better communicate to search engines what a website is really about.

On-page SEO

This one is pretty straightforward. These are all of the little things you do with your content on a page to help it rank better, including optimizing your title for a particular keyword, using H1 and H2 headings and subheadings appropriately, and so on.

Technical SEO

Technical SEO refers to "under the hood" stuff with your website that impacts performance — specifically, how well your site pages rank in search engines. Technical SEO has become increasingly important as Google and other search engines weight site performance heavily when determining how well a website's content ranks overall.

For example, site speed and page load time are massively influential search ranking factors that can bury an otherwise perfectly optimized piece of content 10+ pages deep on Google. It's not enough to create good content anymore. The experience you create for users — including how fast someone can access your content — must be on point.

Of course, these are only a few examples of the most common SEO activities practiced by digital marketers, but hopefully it paints a more accurate and fuller picture of what constitutes SEO.

Common SEM activities and tactics

In addition to SEO sometimes falling under what is considered an SEM (search engine marketing) tactic, Google Ads or pay-per-click (PPC) is probably the most common search engine marketing tactic. That's because you are literally marketing your website and your content on search engines. 

Pretty simple, right?

Even social media marketing, from a paid search perspective, can be considered an SEM activity.

Bottom line, search matters

No matter which set of activities and tactics you're talking about, SEO and SEM are part of the digital marketing landscape in a very permanent way. Search engines will continue to change and evolve, as will how we look to our robots to help us discover the answers to our most pressing questions. 

But we will never stop optimizing for search and marketing for search engines.