IndexedDB is a low-level API for client-side storage of significant amounts of structured data, including files/blobs. This API uses indexes to enable high performance searches of this data. While DOM Storage is useful for storing smaller amounts of data, it is less useful for storing larger amounts of structured data. IndexedDB provides a solution. This is the main landing page for MDN’s IndexedDB coverage — here we provide links to the full API reference and usage guides, browser support details, and some explanation of key concepts.
Peter Vogel. Visual Studio Magazine. 2016-08-30.