SEO Glossary: What the Terms Mean and What to Do

Most SEO reports read like a list of abbreviations. You get a line saying "duplicate canonical, noindex, CLS 0.34" and nobody finishes the sentence — what does that mean for your site, and does it need fixing this week or never?

This glossary works the other way round. For every term I say what it is, where you would actually see it on your site, and whether it's worth your time.

I've grouped the terms by what they touch: indexing, on-page content, links, speed and measurement. You don't need to memorise any of it. You need to understand the sentence when a tool or an agency tells you something is broken.

Indexing: whether Google knows your page exists

Crawl — Google downloads pages with a bot. The bot hits a URL, reads the HTML, finds links and moves on. If no link points to a page and it isn't in your sitemap either, the bot may not reach it for a long time.

Index — the database Google builds results from. A crawled page is not automatically an indexed page. Google can read it and decide not to store it, typically with thin or duplicate content. In Search Console you'll find this under Page indexing, with statuses like "Crawled – currently not indexed".

robots.txt — a text file at the root of your domain telling bots where not to go. It is not an indexing ban. If a page is blocked in robots.txt but another site links to it, it can still show up in the index — just without content.

noindex — a meta tag in the page head saying "keep this out of search results". This one is a real ban. The most common mistake I find: noindex left on the production site after a migration from staging. The page is fine, nobody can find it.

Canonical — a pointer to the main version of a page when the same content lives on several URLs. Shop filters, pagination parameters, URLs with and without a trailing slash. The canonical says which one should be judged. When it helps and when sites hurt themselves with it, I cover in the piece on canonical tags and duplicate content.

sitemap.xml — a list of URLs you want indexed. It guarantees nothing, but it helps the bot find pages that no decent internal link points to. Noindexed URLs and redirected addresses don't belong in it.

301 and 302 — redirects. A 301 is permanent and passes link value to the new address. A 302 is temporary. When you change URL structure or retire categories, you want a 301.

On-page: what Google reads and what the customer sees

Title tag — the text in the page head that shows as the blue headline in search results. Google truncates it by pixel width, roughly 55 to 60 characters. On larger sites this is the single biggest source of errors: dozens of categories carrying the same text, or just the company name. Why it costs you and how to fix it in batches is in how to fix duplicate title tags.

Meta description — the two or three lines under the title. Not a ranking factor, but it decides whether someone clicks. Google rewrites it when it doesn't match the query, which is exactly why being specific pays. A sensible length is around 150 to 160 characters. For shops I go through this in ecommerce meta descriptions.

H1 — the main heading inside the page content. Not the same thing as the title tag. One per page, and it should say what the page is about.

Alt text — the text description of an image in the alt attribute. Screen readers read it, it shows when the image fails to load, and Google uses it to understand what the image contains. Good and bad examples are in image alt text and SEO.

Structured data (schema.org) — machine-readable facts about your content: price, availability, rating, author, opening hours. They can make your result look richer in search. When they're broken, Google ignores them — usually a required field is missing or a value has the wrong type. The checking process is in structured data errors.

Words and intent

Keyword — a query people type into a search engine. Not the word you think is important. "air conditioning installation cost" and "air conditioning units" differ in who is searching and what they want.

Search intent — what the person behind the query actually wants. Informational (wants an explanation), transactional (wants to buy), navigational (wants a specific page). Send an informational query to a product category page and it won't work, however clean the page is technically.

Long tail — longer, more specific queries with lower search volume. For small businesses they're usually worth more, because you can realistically rank for them and the intent is obvious.

Cannibalisation — two or more of your pages competing for the same query. Google can't decide which to favour and swaps them around. You fix it by merging the content into one page or clearly splitting the intent.

Links

Internal links — links between pages on your own site. They tell Google which pages your structure treats as important, and they decide where the bot can get to. Categories reachable only from the main menu usually rank poorly — more in ecommerce internal linking.

Backlink — a link from another site to yours. Quality matters more than count.

Anchor text — the text people click. "Here" says nothing; "ecommerce meta descriptions" says something.

Nofollow — a link attribute saying you don't vouch for the destination. Used for paid links and user comments.

Domain Authority, DA, DR — scores from third-party tools, not from Google. Google publishes no public domain score. They're useful for comparing sites against each other, but they tell you nothing about why one specific page isn't growing.

Speed: Core Web Vitals

Three metrics Google measures on real Chrome visitors. Thresholds for a good result:

• LCP (Largest Contentful Paint) — when the largest content element finishes rendering. Good is under 2.5 seconds.
• INP (Interaction to Next Paint) — how fast the page responds to a click or tap. Under 200 ms.
• CLS (Cumulative Layout Shift) — how much the content jumps around while loading. Under 0.1.

Speed is a ranking factor, but a weak one — it won't beat better content. Bad Core Web Vitals mainly increase the number of people who leave before the page finishes loading. The practical view is in site speed and Core Web Vitals.

Measurement: the numbers in Search Console

Impressions — how many times your page appeared in results. Not visits.

Clicks — how many times someone clicked it.

CTR — clicks divided by impressions. Lots of impressions and few clicks usually means the title and description are the problem, not the content.

Average position — the mean position across all impressions. It's a blunt number; a single appearance at position 40 skews it more than you'd expect.

Queries — the exact phrases your site appeared for. This is the cheapest source of article topics there is: look for queries with impressions and almost no clicks. My process is in finding blog topics in Google Search Console.

Search Console keeps data for 16 months. When I judge whether a change did anything, I compare the 28 days before a fix went live with the 28 days after — a shorter window is just noise. How to do that honestly is in measuring SEO impact.

Terms that get used wrong

Meta keywords — a head tag listing keywords. Google hasn't used it for ranking in many years. If someone bills you for filling it in, you're paying for nothing.

PageRank — the original link-scoring algorithm. Google killed the public number, so "PageRank 5" means nothing today.

Position one — rankings move slowly and depend on competitors you don't control. Anyone promising a specific position by a specific date is talking about something they can't influence.

What to do with this list

A glossary fixes nothing by itself. To know which of these terms apply to your site, you need a list of specific findings with URLs, not general advice. I crawl the public pages, list the errors — duplicate titles, missing alt text, broken structured data — and for the findings that matter I write the finished fix text, which you approve. What an audit shows and what it can't see is in free SEO audit. And if you'd rather work through it yourself, there's a separate piece on DIY SEO without an agency.