g. Indexed DB
APIs for a database of records holding simple values and hierarchical objects. Each record consists of a key and some value. Moreover, the database maintains indexes over records it stores. An application developer directly uses an API to locate records either by their key or by using an index.
More information and examples can be viewed at https://www.w3.org/TR/IndexedDB/
Tutorials on IndexedDB with examples can be found at https://code.tutsplus.com/tutorials/working-with-indexedb--net-34673
The latest versions of Browser Chrome, Mozilla Firefox, Safari all support many HTML5 features and Internet Explorer 8+ will also have support for some HTML5 functionality. The mobile web browsers that come pre-installed on iPhones, iPads, and Android phones all have support for HTML5. HTML5 is also native to any environment, which can host a browser, making HTML5 apps easy to display everywhere so HTML5 can be future of app development