Extensions are small software programs that customize the browsing experience.
They enable users to tailor Chrome functionality and behavior to individual needs or preferences.
This means extensions do not depend on content from the web, unlike ordinary web apps
An extension must fulfill a single purpose that is narrowly defined and easy to understand. A single extension can include multiple components and a range of functionality, as long as everything contributes towards a common purpose.
A screenshot of an extension’s icon in the browser barUser interfaces should be minimal and have intent. They can range from a simple icon, such as the Google Mail Checker extension shown on the right, to overriding an entire page.
Extension files are zipped into a single .crx package that the user downloads and installs. This means extensions do not depend on content from the web, unlike ordinary web apps.
Extensions are distributed through the Chrome Developer Dashboard and published to the Chrome Web Store.