Get started learning the basics of search engine optimization – how SEO works, why it's important, the different types of SEO and much more. What is SEO - search engine optimization SEO stands for Search Engine Optimization and helps search engines understand your website’s content and connect it with users by delivering relevant, valuable results based on their search queries. The goal of SEO is to rank on the first page of search engine results pages (SERPs) for the most relevant and valuable keywords to your target demographic, driving qualified traffic to your site. SEO is considered a digital marketing practice and can be applied to any website. It helps improve a site’s visibility on search engines like Google and Microsoft Bing. Whether your site promotes products, offers services, or shares expert knowledge on a specific topic, SEO can help drive traffic and increase online visibility. The better visibility your pages have in search results, the more likely you are to be found and visited. This introductory guide will explain in more detail what SEO is and what it entails in 2025. Technology is constantly evolving, which means that websites – and the way they are structured – evolve. So do the devices we use to access search engines. A web search can be voice activated and a click may be a tap on a mobile phone screen. Even the results we see from our search engine of choice may be summarized by artificial intelligence (AI). We will explain all these different aspects of SEO as well as provide resources for your continued learning. Table of contents How SEO differs from SEM and PPC Why SEO is important Types of SEO and specializations How does SEO work? How SEO evolves SEO as a service How to learn SEO How is SEO different from SEM and PPC? SEM and PPC are two other common terms you will read about often here on Search Engine Land and hear about in the larger search marketing community. It can also be helpful to distinguish what SEO is from what it is not. Here, we’ll explain the difference in terminologies, what these abbreviations mean and how they extend to different disciplines. SEO vs. SEM SEM stands for search engine marketing – or, as it is more commonly known, search marketing. Search marketing is a type of digital marketing. It is an umbrella term for the combination of SEO and PPC (pay-per-click, e.g. Google Ads) activities that drive traffic via organic search and paid search, respectively. So how do SEO and SEM differ? Technically they aren’t different – SEO is simply one-half of SEM: SEO: Driving organic results clicks from search engines. SEM: Driving organic and paid results clicks from search engines. PPC: Driving paid results clicks from search engines.