Website Health Terms Explained: Plain-English Definitions for Small Business Owners

Explaining the technical terms

If you have ever received a website report, an SEO audit, or a message from a developer and thought, "I have no idea what this means", you are not alone.

When it comes to websites, much like any industry, there are a lot of technical terms, acronyms, and confusing words. It can feel overwhelming trying to navigate through the fog of tech terms when all you want to know is if your website is healthy and working well.

This post is here to remove the fog.

It is a plain-English glossary of the terms that non-technical business owners most often bump into when talking about website health. No jargon. No scaremongering. Just clear explanations and a calm sense of what matters.

How to use this glossary

• Use Ctrl+F (or Find on your phone) to jump to the term you have seen.

• If you work with a developer or agency, copy the definition and paste it into your email so you are both talking about the same thing.

• Remember: not every technical term is a crisis. Some things are urgent, some are important, and some are just tidy-ups.

Status codes, errors, and redirects

When people talk about ‘a 404’ or ‘a 301’, they are usually talking about HTTP status codes. These are short messages your website returns to say what happened when a page was requested. Most of the time, you never notice them, but they show up in website reports because they are a quick way to spot issues. Broken pages, broken journeys, and problems that can quietly cost you enquiries.

200 OK

This means the page loaded properly and everything is working as expected. For normal pages you want people to visit, this is the result you want to see almost all of the time. If a key page is not returning 200, it often points to a bigger issue, such as a missing page, a redirect problem, or a server error.

301 redirect

This means a page has moved permanently to a new address. It is used when you rename a page, change your website structure, or replace old content with a new page. Using a 301 redirect makes sure visitors (and search engines) end up in the right place without hitting an error. A 301 is generally the ‘clean’ way to handle old links, bookmarks, and Google results that still point to an older URL.

302 redirect

This means a page has moved temporarily. It is useful for short-term situations, like sending people to a temporary announcement page or running a short campaign. If a move is actually permanent, using a 302 can cause confusion over time because it suggests the old page may return.

404 error

This means the page cannot be found. It usually happens when a page was deleted, a URL was changed without a redirect, or a link was typed incorrectly. A handful of 404s is normal on many large sites. 404s become a real problem when they affect important pages (like services, pricing, contact, or booking pages). Even worse when your own website buttons take people to missing pages!

410 error

This means the page is gone on purpose and is not coming back. It is similar to a 404, but more definite. In practice, most business owners never need to choose between 404 and 410, but it can show up in reports if pages have been deliberately removed.

500 server error

This means something went wrong on the website’s server, and the page could not load properly. Unlike a 404, which is usually a missing page, a 500 error can point to a deeper technical issue that may come and go. If you see 500 errors on important pages, treat it as urgent as it can stop people using your website even if everything looks fine when you check later.

Broken link

A broken link is a link that takes people to a page that does not work, often a 404, but sometimes a 500 or another error. Broken links are frustrating for visitors and can break key journeys, like getting to your contact page, booking form, or product pages. They also make a site feel neglected, even if the issue is small.

Redirect chain

A redirect chain is when a link goes through multiple redirects before reaching the final page. For example, Page A redirects to Page B, which redirects to Page C. This usually happens after several rounds of website changes, where redirects were added on top of older redirects. Chains can slow things down and make it easier for something to break later.

Redirect loop

A redirect loop occurs when redirects send a browser in circles, meaning the page never loads. For a visitor, it looks like the site is broken. Loops often happen when redirects are set up incorrectly, such as redirecting Page A to Page B, while Page B redirects back to Page A.

Search and SEO terms (the ‘why am I not showing in Google?’ section)

When your site is not showing up properly in Google, the cause is often simpler than it sounds. Most of the time, it comes down to whether Google can find your pages, understand what they are about, and decide they are worth showing. This section explains the terms you are most likely to see in SEO tools, audits, and Google Search Console.

SEO

SEO stands for search engine optimisation. In plain terms, it is the work of helping search engines understand your pages and helping the right people find them. Good SEO is usually more about clarity and structure than tricks.

Crawl (or crawling)

Crawling is when search engines send automated visitors (often called bots or crawlers) to discover pages on your website. If a page is hard to reach, hidden behind broken links, or blocked by settings, it may not get crawled often, or at all.

Index (or indexing)

Indexing is when a search engine stores a page in its database so it can potentially show it in search results. A page can exist and even be crawled, but still not be indexed, which is why some pages never appear in Google.

Robots.txt

A robots.txt is a small file that can tell search engines which parts of your site they are allowed to crawl. It is useful for guiding crawlers away from low-value areas, but if it is set up incorrectly, it can block important pages from being discovered. Google’s own guide explains what a robots.txt file does.

XML sitemap

An XML sitemap is a file that lists the pages you consider important, so search engines can find them more easily. It is especially helpful for newer sites or sites with lots of pages, but it does not guarantee rankings.

Canonical URL

A canonical URL is the ‘main’ version of a page when there are multiple similar versions. The most common example is that www.site.com is the same as site.com. Having a clear 'main version' helps search engines avoid confusion when the same content can be reached through different URLs, such as with tracking links or multiple page variations. Google calls this process canonicalisation.

noindex

noindex is a setting that tells search engines not to include a page in search results. It is useful for pages you do not want appearing in Google, but it can also be the reason a perfectly good page is not showing up if it has been applied by mistake.

Title tag (page title)

The title tag is the main title that often appears as the clickable heading in Google results, and it also shows in browser tabs. A clear page title helps both search engines and humans understand what the page is about at a glance.

Meta description

The meta description is a short summary that search engines may use under the title in results. It does not guarantee better rankings, but it can improve clicks by setting expectations clearly. Google explains how snippets work, including where descriptions can come from.

H1, H2, and headings

Headings are the structure of a page, like headings in a document. A good heading structure makes your page easier to scan, helps people find what they need quickly, and makes the page easier for tools to interpret. The H1 heading is usually the big title at the top of the page, the H2 introduces each new section, H3 is a section title within a section. The number goes down as the importance goes down.

Alt text

Alt text is a short description of an image that helps people using screen readers and helps explain images when they cannot load. It is also a helpful way to make sure images contribute meaningfully to the page, rather than being decorative clutter.

Structured data (schema markup)

Structured data is extra code that helps search engines understand what your content is. For example, whether something is a service, a review, an event, or an article. It can support richer search results in some cases. You see Schema when you search for a recipe online, and in the search results are things like ingredients, time and reviews.

Google Search Console

Google Search Console is a free Google tool that shows how your site is performing in search and flags common issues. If you are trying to understand why a page is not showing in Google, Search Console is often the first place to look.

Speed and performance terms (including Core Web Vitals)

Speed is not just about impatience. A slow, jumpy, or unresponsive site can quietly reduce trust, increase drop-offs, and make it less likely someone completes a form or booking. These are the most common speed terms people see in performance tests and reports.

Page speed

Page speed is a general phrase for how quickly a page feels to a visitor. It is not one single number. It usually includes loading time, how quickly the main content appears, and whether the site reacts quickly when someone taps or clicks.

PageSpeed Insights

PageSpeed Insights is a Google tool that tests a page and reports performance information, including Core Web Vitals. It is a useful way to get a consistent view of how pages are performing and what is holding them back.

Lighthouse

Lighthouse is an automated audit tool that checks performance, accessibility, SEO, and more. It is often used inside other tools, which is why Lighthouse-style wording appears in many reports. Chrome Developers has a clear overview of Lighthouse.

Core Web Vitals

Core Web Vitals are a set of measurements that focus on real user experience, mainly loading, responsiveness, and visual stability. You do not need to memorise them, but you should recognise them because they are commonly used in modern performance reporting. Google’s Core Web Vitals guidance explains what they measure.

LCP (Largest Contentful Paint)

LCP measures how quickly the main piece of content becomes visible, which usually reflects how fast the page feels when it first loads. If LCP is slow, visitors often feel like the page is heavy or sluggish, especially on mobile.

INP (Interaction to Next Paint)

INP measures how quickly the site reacts when someone interacts, like tapping a button, opening a menu, or submitting a form. If INP is poor, the site can feel laggy even if it loads quickly.

CLS (Cumulative Layout Shift)

CLS measures how much the page layout jumps around while loading. This is the classic problem where you go to tap something and the page shifts, so you tap the wrong thing. It often comes from images or banners loading without reserved space.

Caching

Caching means storing a saved version of parts of your site so it can load faster the next time someone visits. Good caching can make a big difference with relatively little effort, especially for returning visitors.

CDN (Content Delivery Network)

A CDN is a network of servers that helps deliver your site’s files faster by serving them from a location closer to the visitor. It is most useful when your visitors are spread across different regions, or when your site uses lots of images and files.

Render-blocking resources

These are files, often scripts or styles, that a browser feels it must load before it can show the page properly. Too many render-blocking resources can delay what the visitor sees, which makes the page feel slow even if it eventually loads fine.

Lazy loading

Lazy loading means images and other elements load only when they are needed, usually as someone scrolls. Used sensibly, it can speed up initial loading and reduce the amount of data a visitor has to download.

Security and trust terms (the padlock stuff)

Security terms tend to feel intimidating, but you can think about them in one simple way. Do visitors see your site as safe and trustworthy? Plus, are your key systems protected from avoidable mistakes like expired certificates or broken DNS?

HTTP vs HTTPS

HTTP is the standard way web pages are delivered. HTTPS is the secure version, which encrypts the connection so data cannot be easily intercepted. Modern browsers expect HTTPS, especially for forms, logins, and payments.

SSL certificate

An SSL certificate is part of what enables HTTPS and the padlock in the browser. People still say ‘SSL’, but the modern protocol is usually TLS. Cloudflare has a plain-English explanation of how SSL and TLS relate.

TLS

TLS is the technology that encrypts the connection between a visitor and your website. It protects things like contact forms, login details, and checkout data.

Certificate expiry

Certificates have an end date. If a certificate expires, browsers often show a warning that can scare visitors away. This is one of those issues that can be easy to prevent but damaging if it is missed.

Mixed content

Mixed content is when a page loads securely over HTTPS, but parts of it still try to load insecurely over HTTP. This weakens protection and can cause browsers to block some elements. Mozilla explains mixed content and why it matters.

DNS

DNS is the system that connects your domain name to the server where your website lives. If DNS settings are wrong, your website can go offline, and email can stop working too.

Nameservers

Nameservers are the service that controls your DNS settings, often your domain registrar or a provider like Cloudflare. If nameservers change unexpectedly, it can point your domain somewhere else, which may break your site or email.

DNS records (A, CNAME, MX)

DNS records are individual settings inside DNS. An A record points a domain to a server’s IP address, a CNAME points one name to another, and an MX record tells email where to go.

SPF, DKIM, and DMARC

These are email protection settings that help prevent people from pretending to send emails from your domain. They also help improve email deliverability, so your genuine emails are less likely to land in spam.

Security headers

Security headers are extra instructions your website sends to browsers to reduce certain risks, such as loading unsafe content or being embedded where it should not be. You do not need to memorise the names, but if a report flags missing security headers, it is usually worth reviewing.

Malware warning

A malware warning means a browser or security service believes the site may be harmful. Sometimes warnings can be false positives. However, they should always be treated seriously because they can stop visitors from trusting your business.

Cookie banner (and cookies)

Cookies are small files used for things like remembering settings, measuring usage, and sometimes tracking behaviour. In the UK, you generally need to explain cookies clearly and get consent for non-essential ones. The ICO explains the rules around cookies and similar technologies.

Accessibility and usability terms (making the site easier for more people)

Accessibility is about making sure more people can use your site comfortably. Many accessibility improvements also improve general usability. It can also reduce friction by making it easier for everyone to complete forms and key journeys around your website.

Accessibility

Website accessibility means designing and building your site so people can use it even if they have impairments. They might use assistive technology or navigate in different ways. It includes things like readable text, clear navigation, sensible structure, and forms that are easy to complete.

WCAG

WCAG is the main set of web accessibility guidelines. It is the standard most tools and audits refer to, and it gives a clear framework for what ‘good’ looks like.

Contrast

Contrast is the difference between the text and the background behind it. Poor contrast makes content tiring or impossible to read for many people, and it is one of the most common accessibility issues on websites.

Keyboard navigation

Keyboard navigation means being able to use a website without a mouse, using keys like Tab to move through links and fields. If a site does not work properly with a keyboard, it can be difficult or impossible for some users to navigate.

Focus state

A focus state is the visible highlight that shows where you are on the page when navigating with a keyboard. Without a clear focus state, keyboard users can lose track of where they are and get stuck.

Form labels

Form labels are the text that tells people what each field is for, like ‘Name’ or ‘Email address’. Labels should be properly connected to the field, not just shown as faint placeholder text, so the form stays clear and accessible.

Tap targets

Tap targets are the buttons and links people press on a phone. If they are too small or too close together, users mis-tap and get frustrated. This is a common usability problem that can directly affect enquiries and bookings.

Readability

Readability is how easy your content is to read and understand. Short paragraphs, clear headings, plain language, and sensible spacing make a site feel calmer. This makes your content more trustworthy, especially for busy visitors scanning on mobile.

A calm rule for what to fix first

If you only remember one thing, let it be this: you do not need to fix everything. You need to fix the right things first.

A simple priority ladder:

1. Anything that blocks enquiries, bookings, or sales (broken forms, broken checkout, broken phone number links).

2. Anything that damages trust (security warnings, expired certificates, obvious broken pages).

3. Anything that blocks visibility (noindex mistakes, robots.txt accidents, missing key pages from your sitemap).

4. Anything that makes the site hard to use (mobile issues, accessibility blockers).

5. Then tidy-ups and improvements (performance tuning, content polish, redirect clean-up).

That keeps things calm, and it keeps the work tied to the real job your website is doing.

Where SiteScanly fits in

If reading this has made you think, "I really just want someone to check this stuff and tell me what matters", that is exactly the point of SiteScanly.

Each month, a SiteScanly report focuses on the areas that most often affect real businesses. It covers Security, Performance, Links, and SEO, with Accessibility and Usability checks on higher tiers.

The aim is not to overwhelm you with technical noise. It is to give you a clear, calm set of priorities you can act on, month after month.

Find out more about SiteScanly's plain-English website health reports and what it would cost to let someone else worry about these technical terms.