SEO stands for search engine optimisation. This page gives the definition, the pronunciation, the terms that surround it, and the two other things "SEO" commonly means so you can tell which one you have found.
SEO stands for search engine optimisation (spelled optimization in American English). It means improving a website so that it appears in the unpaid results of a search engine when someone searches for what that site offers.
The word "unpaid" carries the distinction. Adverts at the top of a results page are bought. Everything below them is earned, and SEO is the work of earning it.
SEO = search engine optimisation. Making a website appear in search results without paying for the click.
Both pronunciations are in common use and neither is wrong. Most people in the industry say it as three letters, "ess-ee-oh". A minority say it as a word, "see-oh", which causes occasional confusion with CEO in conversation.
As a term it works as a noun in two ways. "We do SEO" describes the activity. "She is an SEO" describes the person doing it, which is industry shorthand instead of a job title most people outside the field would recognise.
Same thing, different spelling. British and Commonwealth English uses the s, American English uses the z. Google treats them as the same query and shows near-identical results for both, so there is no ranking advantage in choosing one.
Use whichever matches the rest of your writing. This site is British, so it uses the s, and mentions the z spelling here because plenty of readers search for that version.
Two other meanings send people to pages like this one, and it is worth naming them so you can tell quickly whether you are in the right place.
Seo as a Korean surname. It is a common family name in Korea, romanised as Seo, and several well-known actors and musicians carry it. If that is what brought you here, this page will not help and no amount of scrolling will fix that.
SEO as an acronym elsewhere. In some organisations it stands for Senior Executive Officer or Chief SEO in a titles context. Neither has anything to do with search engines.
Once you have the definition, these are the terms you will meet immediately afterwards.
The definition tells you what it is. It does not tell you what anyone doing it spends their week on, which is a fair next question.
In practice the work divides into three areas. Technical SEO makes sure a search engine can reach, load and understand your site. On-page SEO makes sure each page answers the search it targets. Off-page SEO is about the credibility the rest of the web lends you, mostly through links.
Our full guide to what SEO is covers all three with diagrams, a step-by-step tutorial you can follow on your own site, and honest timelines for how long any of it takes.
If the definition is what you needed, you are done. If you want to know how it works, the complete guide is the next page.
Our Local SEO service covers exactly this, built around your own audit findings.
Search engine optimisation. It is the practice of improving a website so it appears in the unpaid search results when people search for what it offers.
Making your website easy for Google to find, easy to understand, and worth trusting, so that when someone searches for what you do, your page is one of the answers they see without you paying for the click.
Most commonly as three separate letters, "ess-ee-oh". Some people say it as a single word, "see-oh". Both are in normal use in the industry and neither is considered incorrect.
Both are correct. The s spelling is British and Commonwealth English, the z spelling is American. Search engines treat them as the same query, so there is no ranking benefit either way.
SEM, search engine marketing, is the umbrella term covering both paid search adverts and SEO. In everyday use most people say SEM when they mean paid ads and SEO when they mean the unpaid side.
PPC means pay per click, the adverts at the top of the results page, where you pay each time someone clicks. SEO earns the unpaid listings below them. Ads stop the moment the budget does. SEO keeps working.
No. SEO is one channel within digital marketing, which also covers paid advertising, social media, email and content marketing. It is usually the highest-intent channel, because the audience arrives already searching for what you sell.
Diagnoses why a site is not appearing for the searches that matter, then fixes it. That covers technical problems, the content of the pages, and the site's credibility across the wider web. Our page on SEO expertise covers what the role should involve.
No single person. The term came into use in the mid-1990s as the first search engines appeared and site owners began working out what influenced their listings. It has been an evolving practice rather than an invention with a date.
Yes, though the results page has changed considerably. Adverts, AI answers and map results now sit above the ordinary listings, so ranking first no longer means being first on the screen. The unpaid results still carry a large share of clicks, and they are the only ones that keep working when you stop paying.
The clicks are. The work is not, whether you pay someone or spend your own time on it. It is better understood as an investment with a delayed return than as free traffic.
White hat means working within the search engines' published guidelines. Black hat means techniques that breach them, such as buying links or generating bulk low-quality pages. Black hat can work briefly and the fall, when it comes, is sudden.
The complete guide on this site is written for exactly that, and includes a six-step tutorial you can run on your own site in an afternoon using only free tools.
Quite possibly, and this page cannot help with that. Seo is a common Korean family name shared by a number of well-known actors and musicians, and it has no connection to search engines beyond the spelling.