Google Chrome provides APIs such as chrome.bookmarks and chrome.tab so that extensions can interact with the browser. Here are the supported chrome.* APIs:

• bookmarks
• extension
• i18n
• pageActions
• tabs
• toolstrip
• windows

Unless the doc says otherwise, methods in the chrome.* APIs are asynchronous: they return immediately, without waiting for the operation to finish. If you need to know the outcome of an operation, then you pass a callback function into the method. [PENDING: update/elaborate on that]