Glossary

Every technical term we use on this site, defined in plain English.

This glossary defines 60 terms from web development, mobile apps, software and data, cloud and security, design, and search — including the newer AI search vocabulary such as GEO, AEO, and llms.txt. Each entry gives a one-sentence definition followed by what it means in practice for a business.

Web Development

API

(Application Programming Interface)

An API is a defined set of rules that lets one piece of software request data or actions from another.

When your website shows live courier tracking or accepts a card payment, it is calling someone else's API. Most business integrations — payment gateways, shipping partners, accounting software — are API work.

Back End

The back end is the server-side part of an application: the business logic, the database, and the APIs that the front end calls.

Users never see it directly, but it determines whether data is correct, secure, and available. Backend mistakes are the most expensive to fix after launch.

Front End

The front end is the part of a website or application that runs in the user's browser and that they see and interact with.

Built with HTML, CSS, and JavaScript, usually through a framework such as React. Front-end quality determines perceived speed, accessibility, and how a site behaves on a phone.

Headless CMS

A headless CMS is a content management system that stores and serves content through an API, without dictating how that content is displayed.

It lets the same content feed a website, a mobile app, and a kiosk. The trade-off is that the front end must be built separately, so it suits content-heavy brands more than simple sites.

React

React is a JavaScript library, created and maintained by Meta, for building user interfaces out of reusable components.

It is the most widely used front-end library, which matters commercially: it is easier to hire for and less likely to be abandoned than niche alternatives.

Responsive Design

Responsive design is an approach where a single website layout adapts fluidly to any screen size rather than serving separate mobile and desktop sites.

It is now a baseline requirement rather than a feature — Google indexes the mobile version of a site first, so a poor mobile experience is a ranking problem as well as a usability one.

REST API

A REST API is an API that exposes data as addressable URLs and uses standard HTTP methods (GET, POST, PUT, DELETE) to read and change it.

REST is the most common style of web API. It is stateless, cacheable, and readable, which makes it a safe default for connecting a website or mobile app to a backend.

Server-Side Rendering

(SSR)

Server-side rendering is generating a page's complete HTML on the server so the browser receives finished content rather than an empty shell it must fill with JavaScript.

It improves first-paint speed and guarantees that search engines and AI crawlers see your content. Prerendering is a related approach that produces the HTML at build time instead of per request.

TypeScript

TypeScript is JavaScript with a type system added, which catches a large class of errors before the code ever runs.

For a business, the benefit is fewer production bugs and faster onboarding of new developers, because the code documents its own expectations.

Webhook

A webhook is an automated message sent from one system to another when a specific event happens.

Where an API is you asking "has the payment cleared?", a webhook is the payment provider telling you the moment it does. Webhooks remove the need to poll and are how most real-time integrations work.

Mobile & Apps

Cross-Platform App

A cross-platform app is a mobile application built from a single codebase that runs on both iOS and Android, typically using Flutter or React Native.

It usually costs close to one build instead of two. The limits show up in graphics-heavy apps and in features that depend on very new OS capabilities.

Flutter

Flutter is Google's open-source framework for building cross-platform applications from one Dart codebase.

It renders its own UI rather than wrapping native components, which gives consistent appearance across platforms and good performance for most business applications.

Minimum Viable Product

(MVP)

An MVP is the smallest version of a product that delivers real value to users and produces evidence about whether the idea works.

The point is learning, not cost-cutting. A good MVP does one job properly; a bad one does ten jobs badly and teaches you nothing.

Native App

A native app is a mobile application written specifically for one platform — Swift for iOS or Kotlin for Android — and distributed through that platform's app store.

Native apps get the best performance and the fullest access to device features, at the cost of building and maintaining two separate codebases.

Progressive Web App

(PWA)

A Progressive Web App is a website that can be installed to a phone's home screen, work offline, and send push notifications, without going through an app store.

It costs far less than a native app and avoids store review entirely. iOS supports PWAs with some restrictions, which is the main reason to still choose native in consumer products.

Service Worker

A service worker is a script the browser runs in the background, separate from the page, enabling offline caching and push notifications.

It is the technology that makes a Progressive Web App work offline and is also used to speed up repeat visits on ordinary websites.

SEO & AI Search

Answer Engine Optimization

(AEO)

AEO is the practice of optimising content to be the direct answer shown to a user, whether in a featured snippet, a voice assistant reply, or an AI-generated summary.

AEO and GEO overlap heavily. The distinction is mostly emphasis: AEO focuses on the answer format, GEO on being the cited source.

Backlink

A backlink is a link from another website to yours, treated by search engines as a signal of credibility.

Relevance and authority matter far more than volume. A handful of links from respected industry sites outperform hundreds from directories, and bought links carry real penalty risk.

Canonical Tag

A canonical tag is a link element that tells search engines which URL is the authoritative version of a page when several URLs show the same content.

It prevents duplicate-content dilution from things like trailing slashes, tracking parameters, and www versus non-www variants.

Core Web Vitals

Core Web Vitals are three Google metrics that measure real-world page experience: Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift.

The targets are LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. They correlate strongly with whether mobile visitors stay on a page.

Crawlability

Crawlability is how easily a search engine bot can discover and read the pages of a website.

It is harmed by pages reachable only through JavaScript interaction, broken internal links, orphan pages with no links pointing to them, and overly restrictive robots.txt rules.

Cumulative Layout Shift

(CLS)

CLS measures how much the content of a page moves around unexpectedly while it loads.

A good score is under 0.1. It is nearly always caused by images without width and height attributes, late-loading fonts, or injected banners and ads.

E-E-A-T

(Experience, Expertise, Authoritativeness, Trustworthiness)

E-E-A-T is the framework in Google's Search Quality Rater Guidelines used to assess whether content comes from a credible source.

It is not a direct ranking factor you can set. It is demonstrated through named authors with real credentials, cited sources, a physical address and phone number, transparent policy pages, and content that shows first-hand experience.

Entity

An entity is a distinct thing a search engine can recognise and reason about — a company, a person, a product, a place — as opposed to a string of keywords.

Search and AI systems increasingly match entities rather than text. Consistent naming, an Organization schema, and presence in sources like Wikidata all strengthen how well your business is recognised as an entity.

Featured Snippet

A featured snippet is the boxed answer Google displays above the normal results, extracted from a page that answers the query directly.

Winning one usually means answering the question in a short, self-contained paragraph, list, or table near the top of the page — the same format that AI engines quote.

Generative Engine Optimization

(GEO)

GEO is the practice of structuring a website so that AI answer engines such as ChatGPT, Google Gemini, Perplexity, and Copilot cite it when generating answers.

In practice it means answering questions directly in the first hundred words, publishing verifiable facts, using FAQ and Organization structured data, and serving content that is readable without JavaScript.

IndexNow

IndexNow is a protocol that lets a website notify participating search engines the instant a URL is added, updated, or deleted.

Bing, Yandex, Naver, and Seznam support it. Because Microsoft Copilot draws on the Bing index, IndexNow is a practical lever for AI search visibility.

Interaction to Next Paint

(INP)

INP measures how quickly a page visibly responds after a user taps or clicks, across the whole visit.

A good score is under 200 milliseconds. It replaced First Input Delay in 2024 and is usually degraded by heavy JavaScript running on the main thread.

JSON-LD

JSON-LD is the JSON-based format Google recommends for embedding structured data in a page, placed in a script tag rather than mixed into the HTML.

Because it sits separately from the markup, it is easier to maintain than older formats such as microdata and is far less likely to break during a redesign.

Knowledge Graph

The Knowledge Graph is Google's database of entities and the relationships between them, which powers knowledge panels and informs AI answers.

Getting a business represented there depends on consistent information across the web, structured data, and citations from sources Google already trusts.

Largest Contentful Paint

(LCP)

LCP measures how long it takes for the largest visible element on a page — usually a hero image or headline — to finish rendering.

A good score is under 2.5 seconds. The usual causes of a poor LCP are oversized images, slow server response, and render-blocking fonts or scripts.

LLM SEO

LLM SEO is the discipline of making content easy for large language models to parse, quote, and attribute correctly.

The tactics that matter most are clear heading hierarchy, short paragraphs, comparison tables, explicit definitions, TL;DR summaries, and consistent naming of your brand and products.

llms.txt

llms.txt is a plain-text file at the root of a website that summarises the site and lists its key pages in a form designed for large language models to read.

It is a proposed convention rather than a formal standard, and it is cheap to add. This site publishes one at /llms.txt.

Mobile-First Indexing

Mobile-first indexing means Google uses the mobile version of a page as the primary basis for indexing and ranking it.

If content, structured data, or links are hidden or missing on mobile, Google effectively does not see them — regardless of how complete the desktop version is.

robots.txt

robots.txt is a file at the root of a site that tells crawlers which parts they may or may not request.

It controls crawling, not indexing — a blocked page can still appear in results if other sites link to it. It is also where AI crawler access is granted or denied.

Schema Markup

Schema markup is structured data added to a page — usually as JSON-LD — that describes its content in a vocabulary search engines and AI systems understand.

It is how you state explicitly that a page is an article, a product, an FAQ, or a local business. It powers rich results in Google and helps AI engines identify facts reliably.

SEO

(Search Engine Optimization)

SEO is the practice of improving a website so that it ranks higher in unpaid search engine results.

It has three parts: technical SEO (can the site be crawled and rendered), on-page SEO (does the content match what people search), and off-page SEO (do other credible sites reference you).

Technical SEO

Technical SEO is the part of SEO concerned with whether a site can be crawled, rendered, and indexed correctly — rather than with what the content says.

It covers sitemaps, robots.txt, canonicals, redirects, site speed, mobile rendering, HTTPS, and structured data. It is the work that has to be right before content work pays off.

XML Sitemap

An XML sitemap is a file listing the URLs on a site that you want search engines to know about, along with when each was last modified.

It helps discovery, especially for new or deeply nested pages, and should be submitted to both Google Search Console and Bing Webmaster Tools.

Software & Data

CRM

(Customer Relationship Management)

A CRM is a system that records every interaction with leads and customers so that sales and support work from one shared history.

A CRM only works if the team actually uses it. The most common failure is a system designed around reporting needs rather than around what a salesperson does daily.

Database

A database is an organised store of structured data that an application reads from and writes to.

Relational databases such as PostgreSQL and MySQL enforce structure and relationships; document databases such as MongoDB trade that for flexibility. The choice constrains everything built on top of it.

ERP

(Enterprise Resource Planning)

An ERP is a single system that manages a company's core operations — inventory, production, purchasing, sales, and finance — on one shared database.

The value is that data is entered once and is consistent everywhere. The risk is scope: phased rollouts succeed far more often than all-at-once implementations.

Legacy System

A legacy system is older software that a business still depends on but that is difficult, risky, or expensive to change.

The problem is rarely age itself — it is that the people who understood it have left and there are no tests, so nobody can change it safely.

SaaS

(Software as a Service)

SaaS is software delivered over the internet on a subscription, with the vendor running the infrastructure, updates, and security.

It has low upfront cost and no maintenance burden. Over several years and many users, per-seat fees can exceed the cost of building and owning an equivalent system.

Technical Debt

Technical debt is the future cost created when a quick implementation is chosen over a sound one.

Some debt is a reasonable trade to reach a deadline. It becomes dangerous when it is never repaid, at which point every new feature takes longer than the last.

Cloud & Security

CDN

(Content Delivery Network)

A CDN is a network of servers distributed worldwide that serves your site's files from a location physically near each visitor.

It is the single most effective change for international audiences: it cuts latency, absorbs traffic spikes, and provides a first layer of defence against attacks.

Cloud Hosting

Cloud hosting is running a website or application on managed infrastructure rented from a provider such as AWS, Azure, or Google Cloud rather than on hardware you own.

You pay for what you use and can scale on demand. The trade-off is that cost and security depend entirely on how well the environment is configured.

Content Security Policy

(CSP)

A Content Security Policy is a response header that tells the browser which sources of scripts, styles, and other resources a page is allowed to load.

It is the strongest available defence against cross-site scripting, because even injected code will not execute if its source is not on the allowed list.

GDPR

(General Data Protection Regulation)

GDPR is the European Union regulation governing how personal data of people in the EU is collected, stored, and used.

It applies to any business processing EU residents' data regardless of where that business is located — which includes Indian companies selling to European customers.

HSTS

(HTTP Strict Transport Security)

HSTS is a response header that instructs browsers to only ever connect to a site over HTTPS, even if a user types an insecure address.

It closes the brief window during a redirect where a connection could be intercepted, and is a standard item on any security audit.

SSL / TLS

SSL, now properly called TLS, is the encryption that secures data travelling between a browser and a website, indicated by HTTPS and the padlock icon.

It is mandatory rather than optional: browsers warn users on sites without it, and it is a confirmed ranking signal. Certificates are free through Let's Encrypt.

Uptime

Uptime is the percentage of time a service is available and functioning correctly.

The numbers are less forgiving than they look: 99.9% permits about 8.8 hours of downtime a year, while 99.99% permits about 53 minutes.

Design

Conversion Rate

Conversion rate is the percentage of visitors who complete a desired action, such as submitting an enquiry or placing an order.

Improving it is usually cheaper than buying more traffic: doubling conversion has the same effect as doubling ad spend, and it compounds across every channel.

Design System

A design system is a documented set of reusable components, colour and type tokens, and usage rules shared across a product.

It keeps a product consistent as it grows and lets developers assemble screens from approved parts instead of reinventing them each time.

Prototype

A prototype is a clickable simulation of a product used to test flows with real people before development starts.

It is the cheapest point at which to discover that a flow confuses users. Fixing the same problem after launch typically costs an order of magnitude more.

UI Design

(User Interface Design)

UI design is the practice of designing the visual and interactive surface of a product: layout, typography, colour, spacing, and states.

Good UI makes the structure that UX established legible at a glance. It cannot rescue a badly structured product.

Usability Testing

Usability testing is watching real users attempt real tasks in a product and recording where they hesitate, fail, or misunderstand.

Five participants typically surface the majority of serious problems, which makes it one of the highest-return activities in product design.

UX Design

(User Experience Design)

UX design is the practice of structuring a product so that people can complete what they came to do with the least friction.

It deals with flow, hierarchy, and information architecture. Most usability failures are structural, which is why UX work precedes visual design.

WCAG

(Web Content Accessibility Guidelines)

WCAG is the international standard defining how to make web content usable by people with disabilities, organised into levels A, AA, and AAA.

AA is the level most regulations reference. It covers colour contrast, keyboard navigation, text alternatives for images, and clear focus indicators — all of which also help search engines and AI crawlers parse a page.

Wireframe

A wireframe is a deliberately plain layout sketch that shows what goes where on a screen, without colour, imagery, or final copy.

Stripping out the visuals keeps review focused on structure and priority, when changes are still nearly free to make.

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