AI website builder glossary

This glossary defines, in one or two sentences each, the terms you will meet when you read about or use an AI website builder. The terms are grouped by where you meet them: the AI itself, building the site, putting it online, measuring its quality, and paying for it.

The short version

• The AI terms describe how the first draft is made.
• The publishing terms (hosting, domain, SSL) describe ordinary web infrastructure that every site needs, AI or not.
• Export and lock-in are the two terms worth understanding before you sign up.

AI terms

Generative AI. Software that produces new text, images or code in response to a request, as opposed to software that only sorts or retrieves existing material.

Large language model (LLM). The kind of generative AI behind every AI website builder. It produces text by predicting a likely sequence of words from patterns in its training data. That makes it fluent and also means it can be confidently wrong.

Prompt. The instruction you type, for example “a website for a mobile dog groomer in Leeds”.

System prompt. The much longer set of hidden instructions a builder places in front of your prompt before the model sees it. It carries the vendor’s rules about structure, tone and format, which is why two builders give different sites from the same sentence.

Token. The unit a language model reads and writes: a word or a piece of a word. The work a model does is counted in tokens, which is what a builder’s AI metering is ultimately based on.

Context window. The amount of text, counted in tokens, that a model can take into account at one time. In a long chat about a large site, early instructions can fall outside it and be forgotten.

Hallucination. A statement the model generates that is false but reads as fact, such as an invented award or founding year. It is the reason to fact-check generated copy.

AI assistant. A chat box inside the editor that carries out requests such as “shorten this paragraph” or “add a pricing section”.

AI agent. An AI system that takes several steps on its own towards a goal, checking results as it goes, instead of answering once. Builders increasingly describe their assistants this way.

Coding agent. An AI agent that works on source code: reading files, editing them, running commands and proposing changes for review. Claude Code, Codex and OpenCode are examples. See Types of AI website builders for where they fit.

Vibe coding. Building software by describing what you want in conversation and accepting the code the model writes. Some website builders now use the phrase for their chat-only mode.

Credits. A vendor’s unit for metering AI use. A request to generate or change something costs some number of credits, and each plan includes an allowance. What one credit buys differs between vendors.

Building terms

Template. A pre-designed site or page that you fill with your own content. Many AI builders start from templates or template parts without showing you.

Section (or block). A reusable strip of a page, such as a hero banner, a testimonial row or a contact form. Hosted builders assemble pages from a library of these, which is what the AI chooses from.

Design system. A vendor’s fixed set of components, spacing rules, type sizes and colour roles. Generated pages are built inside it, which keeps them tidy and also makes sites from one builder resemble each other.

Rendering. Turning a stored description of a page, or its source code, into the HTML that a browser displays. In a hosted builder the vendor’s software does this each time, which is why the site cannot simply be copied elsewhere.

Drag-and-drop editor. A visual editor in which you move, resize and change elements directly on the page, with no code.

Responsive design. A layout that rearranges itself to fit phones, tablets and desktops. You should still look at the phone version yourself.

CMS (content management system). The part of a website tool that stores repeating content, such as blog posts, products or team members, separately from the design, so that adding an item does not mean designing a page.

Static site. A website made of ready-made files that are sent to every visitor unchanged. Static sites are quick and cheap to host. Features such as logins or a shopping cart need something more.

Source code. The text files (HTML, CSS, JavaScript and others) that a browser or server turns into a website. Hosted builders hide it. Prompt-to-code tools and coding agents produce it.

Repository. A folder of source code tracked by a version-control system, almost always Git, which records every change and who made it. Often stored on a service such as GitHub.

Diff. A view showing exactly which lines of code a change added and removed. It is how the work of a coding agent is reviewed.

Publishing terms

Hosting. The service that stores your site and delivers it to visitors. With a hosted builder it is included and you cannot swap it.

Domain name. Your address on the web, such as example.com, rented yearly through a registrar.

Subdomain. An address under someone else’s domain, such as yourname.buildername.com. Free plans usually publish here.

Custom domain. Your own domain connected to the site, in place of the builder’s subdomain. Connecting one generally requires a paid plan.

DNS. The system that maps a domain name to the server hosting the site. “Pointing your domain” means editing DNS records at the registrar.

SSL certificate (TLS). The certificate that lets a site load over https and encrypts traffic between the visitor and the server. Builders normally issue one automatically and include it in the plan.

CDN (content delivery network). A set of servers around the world that keep copies of your site’s files, so each visitor is served from somewhere nearby.

Publish. The action that makes your draft visible at a public address. Check which plan allows it; some trials only produce a private preview.

Search and quality terms

SEO (search engine optimisation). The work of making pages easy for search engines to understand and worth showing to searchers.

Title and meta description. Two fields in a page’s code that search engines can show as the headline and summary of a result. Google’s snippet guidance recommends a description that accurately describes the specific page.

Alt text. A written description attached to an image, read aloud by screen readers and used by search engines.

Structured data. Machine-readable labels in a page that tell search engines what something is, for example a business address, a product price or a set of questions and answers.

Sitemap. A file listing the pages of a site so that search engines can find them all.

Core Web Vitals. Google’s three measures of page experience: loading (Largest Contentful Paint), responsiveness (Interaction to Next Paint) and visual stability (Cumulative Layout Shift). The thresholds are published on web.dev and explained in What to check before you choose.

Accessibility. How well people with disabilities can use the site. The reference standard is the W3C’s WCAG, with conformance levels A, AA and AAA.

Ownership and cost terms

Export. A feature that lets you download your site or its content. What it includes varies widely, from full source code to a partial file of text and images.

Lock-in. The situation where a site can only run on the platform that created it, so that leaving means rebuilding.

Open source. Software whose source code is published under a licence that lets anyone use, change and share it. An open-source tool is free to install; services it relies on, such as an AI model, may not be free.

Free plan and free trial. A free plan has no end date and has permanent limits, commonly a subdomain and vendor branding. A free trial is the full product for a limited time. Vendors use both words loosely, so read what is actually published and for how long.

Renewal price. The price after an introductory discount or a free first year ends. It is the figure to budget with.

For how these pieces fit together when a site is generated, read How AI website builders work.

Frequently asked questions

What does LLM mean in an AI website builder?

LLM stands for large language model, the kind of AI that writes text by predicting likely next words. In a website builder it plans the pages, writes the copy and chooses or describes the layout. It does not host the site or process payments, and it can state things that are untrue.

What is the difference between a domain and hosting?

A domain is the address people type, such as example.com, which you rent by the year from a registrar. Hosting is the computer that stores your site and sends it to visitors. A website builder bundles hosting into its subscription, and usually sells or connects a domain as a separate step.

What does lock-in mean for a website?

Lock-in means your site only works on the platform that made it, so leaving requires rebuilding it somewhere else. It comes from proprietary page components, limited export features and services such as shops or bookings that are tied to the vendor. Keeping your own copies of text and images reduces the cost of leaving.

What is a coding agent?

A coding agent is an AI system that works on a software project the way a developer would. It reads the files, edits them, runs commands and offers the result for review. Claude Code, Codex and OpenCode are examples. It differs from a website builder in that it works on source code in a repository you control.