SEO Basics: How Search Engines, Keywords and Technical SEO Work

SEO, short for search engine optimization, is the work of helping search engines understand your pages so the right people find them. Google's own SEO starter guide puts it as helping "search engines understand your content". Everything below, from keywords to page speed, is a part of that one job.

"Some changes might take effect in a few hours, others could take several months."

Google Search Central, SEO Starter Guide, read on 5 November 2026

This page replaces seven shorter guides. Each section answers one question first, in a few sentences, and then gives the essentials. Where a claim is about how Google behaves, it links to Google's documentation. The last section connects the basics to expired domains, which is what the Revised directory lists.

What is SEO and how long does it take to work?

SEO is the practice of making a site easier for search engines to find, read and rank, and more useful to the people who arrive from search. The traffic it earns is called organic because nobody pays per click. Results are slow, and Google says changes can take anywhere from hours to months to show.

Three areas cover most of the work.

• Content. Pages that answer what people actually search for, in words they use.
• Technical. A site that search engines can reach, read and index without errors.
• Authority. Links and mentions from other sites that show your pages are worth citing.

Paid search is a different thing. Google states plainly that it "doesn't accept payment to crawl a site more frequently, or rank it higher" in organic results, so no spend moves an organic ranking.

The same Google guide suggests waiting "a few weeks" before judging the effect of a change. That is a sound rule for a beginner. Change one thing, wait, then look at the data in Google Search Console. Its Performance report shows clicks, impressions, click-through rate and average position, and the Queries tab groups them by the search terms people typed.

SEO has no finish line. Pages age, competitors publish, and search engines change how they rank. Treat it as a routine of publishing, checking and fixing, not a project that ends.

How do search engines work?

A search engine finds pages by following links, stores what it finds in an index, and ranks the stored pages when someone searches. Google describes three stages: crawling, indexing and serving results, and says "not all pages make it through each stage". Each stage can fail for a page independently.

Crawling. A program fetches pages. Google's is called Googlebot, and Google says it "uses an algorithmic process to determine which sites to crawl, how often". It finds new pages mostly by following links from pages it already knows, and from sitemaps you submit. A sitemap is a file listing the pages on your site. It helps discovery but "doesn't guarantee that all the items in your sitemap will be crawled and indexed."

Indexing. The search engine reads each fetched page and stores what it understood: the text, the images, the title, the language, and which URL is the main version of duplicate pages. Google is plain that "Indexing isn't guaranteed; not every page that Google processes will be indexed." The rel="canonical" link is described as "a strong signal that the specified URL should become canonical", which is how you tell Google which duplicate to keep.

Serving. When someone searches, ranking systems pick from the index. Google's ranking systems guide says automated systems weigh "hundreds of billions of web pages" and "look at many factors and signals". It does not publish a list of factors, and nobody outside Google can give you one with confidence.

Links matter at two points. They are how crawlers discover pages, and they are one of the signals that a page is worth showing. That is why backlinks sit under the authority part of SEO. Referring domains versus backlinks explains which count to watch.

You control more of this than it seems. A robots.txt file manages crawl traffic, but Google's robots.txt introduction says it "is not a mechanism for keeping a web page out of Google". To keep a page out of results, use a noindex directive or password protection.

What are keywords in SEO?

Keywords are the words and phrases people type into a search engine, and the terms you build a page around so it can match them. A keyword is not a tag you hand to Google. It is a topic, expressed in the exact words your audience uses, that a page should answer well.

Keyword research is the process of finding those phrases and choosing which to target. A short routine works for most sites.

1. List the topics your site covers, in plain words.
2. Search each one and read what ranks. The results show what Google thinks the phrase means.
3. Check a keyword tool for the volume and difficulty of the candidates. Treat both as estimates, since different tools report different numbers for the same phrase.
4. Pick one main phrase per page, plus the close variants a reader would use.
5. After publishing, read the Queries tab in Search Console. It shows the phrases the page really appears for, which are often not the ones you chose.

Phrases come in sizes. Short terms such as "backlinks" have large volume and many competing pages. Longer phrases such as "how to check backlinks for a new site" have less volume, are easier to win, and state the need more clearly. A new site usually gets further with the long ones.

Put the main phrase where a reader expects it: the title, the first heading, the opening paragraph, and the page URL. Google's guide says a good title "is unique to the page, clear and concise, and accurately describes the contents of the page", and a good meta description "is short, unique to one particular page, and includes the most relevant points of the page."

Repeating a phrase more often does not help. Writing for a phrase instead of a reader produces text that reads badly, and Google's spam policies list keyword stuffing, which they define as "the practice of filling a web page with keywords or numbers". Use the phrase naturally and cover the topic fully.

The keyword difficulty checker is a quick way to compare candidates.

What is a SERP?

A SERP, or search engine results page, is the page a search engine returns for a query. It shows more than ten blue links. Google's Visual Elements gallery describes the building blocks of a results page, including text results, rich results, image results, video results and sitelinks.

What appears depends on the query. A question may bring a direct answer and a panel of related questions. A product search brings shopping results. A local search brings a map. Two people searching the same words can see different pages, because location, device and language change the results.

This matters for three reasons.

• Position is not one number. Rank 1 on a page with an answer box, a map and ads can sit lower on the screen than rank 4 on a plain page.
• Many searches end without a click. SparkToro's study of clickstream data, published July 2024 and flagged by its authors as possibly out of date, found 58.5% of US Google searches ended with no click, and that 360 clicks per 1,000 US searches reached the open web.
• Features are chances. Structured data makes pages eligible for special results. Google says "valid structured data on your pages also makes your pages eligible for many special features in Google Search results", and its structured data guide is careful to say markup does not guarantee a rich result.

To see your own SERP position, use the Search Console figure for average position, or search in a private window and note that your own results are personalised. Rank trackers are useful for trends and unreliable as a single reading.

What is search intent?

Search intent is the reason behind a search: what the person wants to do when they type it. Matching it is often the difference between a page that ranks and one that does not, because a search engine tries to return pages that satisfy the need and not just pages that contain the words.

Four types cover most queries.

The labels are a working classification used across the industry, and real queries blend them. Many have no single answer.

You can read intent without a tool. Search the phrase and look at what ranks. If the top ten are all guides, a product page will not break in. If they are all product pages, a long explainer will struggle. The search engine has already voted on what the phrase means, and your page has to be the same kind of page.

Intent also shows in the wording. "How", "what" and "why" lean informational. "Best", "vs" and "review" lean commercial. "Buy", "price" and "near me" lean transactional. A brand name usually means navigational.

Mismatch is the usual failure. A page can be accurate, well written and well linked and still fail because it answers a different question than the one the phrase asks. Fix it by matching the format of what ranks, and by saying what the page is for in its first paragraph.

What is technical SEO?

Technical SEO is making sure search engines can reach, read and index your site. It covers the parts that sit under the content: whether pages load, whether crawlers are allowed in, whether duplicates are handled, and whether the site works on a phone. A site with strong content and a technical fault can still be invisible.

A short checklist covers the essentials.

• Crawlability. Pages you want found are linked from other pages and not blocked in robots.txt. Submit a sitemap.
• Indexability. Pages you want in search return a normal status, carry no noindex, and name one canonical URL. Use noindex, not robots.txt, to keep a page out.
• Structure. Short, readable URLs and a shallow link structure, so important pages are a few clicks from the home page.
• Mobile. Google indexes the mobile version: it "uses the mobile version of a site's content, crawled with the smartphone agent, for indexing and ranking." Google's advice is "Make sure that your mobile site contains the same content as your desktop site."
• HTTPS. Google announced HTTPS as a ranking signal on 7 August 2014 and called it "a very lightweight signal" affecting "fewer than 1% of global queries". It is a baseline for trust more than a way to gain rank.
• Structured data. Markup that describes the page, covered above under SERPs.
• Speed. Covered in the next section.

For a site with many pages, the same ideas apply at scale. Duplicate URLs, faceted pages and broken internal links waste crawling. Crawl a staging copy before launch, and check Search Console's indexing reports after.

Run an audit on a schedule. A crawler such as Screaming Frog, or Search Console's own reports, will list blocked pages, redirect chains, missing titles and error responses. Fix the ones that sit on pages you care about first.

What are Core Web Vitals?

Core Web Vitals are three measurements of how a page feels to use: how fast the main content loads, how quickly it responds to input, and how stable the layout stays. Google ties them to what its core ranking systems seek to reward, and a good score helps. It does not guarantee a ranking.

The thresholds are from Google's Core Web Vitals documentation and web.dev's guide to the metrics, read on 5 November 2026. web.dev adds that "a good threshold to measure is the 75th percentile of page loads", which means 75% of real visits should meet the target, not just the average.

Search Console has a Core Web Vitals report that shows how your pages perform. Fix what it flags on your most important pages first. The usual causes are large unoptimised images and slow servers for LCP, heavy scripts for INP, and images or ads with no reserved space for CLS.

Treat speed as a tiebreaker, not a strategy. A fast page with nothing useful on it does not rank. A slow page that is the best answer often still does.

Where do expired domains fit into SEO basics?

An expired domain is a name whose registration lapsed and which anyone can now register. If other sites linked to it while it was live, those links can still exist, and the authority part of SEO is the slowest to build. That is the reason people look at expired domains. It is not a shortcut around the rest.

Everything above still applies to a registered expired domain. It has to be crawled, indexed and given useful content that matches an intent, and Google's rules turn on what you publish afterwards. The complete guide to expired domains covers the timeline, the risks and how to find them. How to get backlinks covers the slower routes that work for any site, including a new one.

The Revised directory lists expired domains that still carry backlinks. Each listing is spam-screened on its site history before it goes up, and the name stays masked until you reveal it. We do not sell, hold or register domains, so you register any name yourself.

• Browse the directory and filter by category so the old links match what you plan to publish.
• Read the Linked by line and the archive timeline before you reveal a name.
• Check any shortlisted name with the backlink checker and the expired domain checker.

FAQ

Is SEO still worth doing? Yes, if organic search sends you visitors. It is slow and has no guarantee, which is why most sites should start by fixing technical faults and publishing pages that answer real questions. Google's guide says changes can take hours to several months to show.

Can I do SEO myself? Yes. The basics need no special tools: clear pages, working links, sensible titles, a sitemap and Search Console. Google's own guide says "you might consider hiring a professional", which is optional and not required.

What is the difference between SEO and paid search? Paid search shows ads you pay for per click. SEO earns unpaid results. Google states it does not accept payment to crawl a site more often or rank it higher, so ad spend does not change organic rankings.

Do I need keywords in the URL and the title? Put the main phrase in the title, heading and opening paragraph, and keep the URL short and readable. Do not repeat the phrase to force a match. Cover the topic and use the words a reader would use.

Why is my page not showing up in Google? Check Search Console's indexing reports first. The page may not be crawled, may be blocked by noindex, or may be a duplicate of another URL. Google says not every page it processes is indexed, so a new page can also just be waiting.

Do Core Web Vitals decide my ranking? No single metric does. Google describes them as aligned with what its core ranking systems seek to reward, and good scores help, but it does not say they guarantee a position. Content that answers the query matters more.