Microsoft's news that it's shifting its Edge web browser onto the Chromium engine has prompted discussion around a broad swathe of different web technologies. If you've found all the names and jargon confusing, you may find this reference of use.
We've put together a cheat sheet of key terms and technologies. It should help you understand the roles of the different projects and what's changing within Edge. Phrases in italics in the definitions indicate a reference to another term within this cheat sheet.
- Browser engine – Core, self-contained component of a web browser responsible for constructing and rendering webpages such that they are visible and interactive. Browser engines are usually opaque to the end user, who is typically unaware of their role in the browsing experience. The engine incorporates several sub-components, such as a layout engine and rendering engine, which implement different required functionalities for constructing webpages.
Browser engines are usually, but not always, standalone components which can be implemented by multiple distinct web browsers – for example, the Chromium engine is currently used by Google Chrome, Opera, Vivaldi and many others. Each of these browsers has a unique interface and user-facing feature set, but relies on the Chromium engine to fetch, construct and render actual webpages.
- Blink – A popular and established open-source browser engine used by multiple web browser projects, including Chromium. Blink is broadly compliant with modern web standards and moves to implement emerging standards and recommendations in a timely manner, which has contributed to its popularity. It was forked from the WebKit engine.
- HTML – Hypertext Markup Language. HTML is the markup language used to create the structure and fundamental layout of webpages. Browser engines use HTML files to construct the webpage which is ultimately rendered to your display.
- PWA – Progressive Web App. A set of development approaches, concepts and technologies which enable websites and web apps to behave like installed native apps on compatible devices.
Features available vary by the platform on which the PWA is being used, but typically include the ability to "install" the website/web app in a manner akin to that of a native app, as well as support for service workers – a web technology which facilitates use of features such as offline operation, background sync and push notifications which are usually associated with native apps.
PWAs are often mischaracterised by the tech media and non-developers as hybrid or hosted web apps. A pure PWA solely uses web standards to provide its functionality and is delivered from a website domain. It's then up to individual platforms to implement the relevant web standards and provide a native-like experience.
This glossary provides a high-level overview of each of these technologies and terms; if you want to learn more, we encourage you to head to the websites of each featured project. Although these technologies may go unnoticed by users, they're instrumental to the web and make it possible for us to consume webpages using our browsers.