Get the current UTC date and time

A Blob object represents an immutable, raw data file-like object. Blobs are used to represent data that isn't always in a JavaScript-native format.
Client-side databases can be used to retrieve blobs.

Blobs are used to represent data that isn't always in a JavaScript-native format.
You can make your own blobs by constructing them with a BlobBuilder object from strings, ArrayBuffer objects, and other Blobs.

The File interface is based on the Blob interface, inheriting blob functionality and expanding it to support files on the user's system.
A File is simply a Blob of data with a name and a modification date in client-side JavaScript.