Document.all - Web APIs
the document interface's read-only all property returns an htmlallcollection rooted at the document node.
... syntax var htmlallcollection = document.all; value an htmlallcollection which contains every element in the document.

Document - Web APIs
document.all provides access to all elements in the document — it returns an htmlallcollection rooted at the document node.

The HTML DOM API - Web APIs
domstringlist domstringmap errorevent htmlallcollection mimetype mimetypearray promiserejectionevent interfaces belonging to other apis several interfaces are technically defined in the html specification while actually being part of other apis.

Index - Web APIs
865 document.all api, dom, deprecated, document, htmlallcollection, property, reference, all the document interface's read-only all property returns an htmlallcollection rooted at the document node.