REST API Merge Proposal, Part 2: Content API

Hi everyone, it’s your friendly REST API team here with our second merge proposal for WordPress core. (WordPress 4.4 included the REST API Infrastructure, if you’d like to check out our previous merge proposal.) Even if you’re familiar with the REST API right now, we’ve made some changes to how the project is organised, so it’s worth reading everything here. (If you haven’t done so already, now would be a great time to install the REST API and OAuth plugins from WordPress.org.)
A brief history of the REST API
The REST API was created as a proof-of-concept by Ryan McCue (hey, that’s me!) at the WordPress Contributor Summit in 2012, but the project kicked off during the 2013 Google Summer of Code. The end result was Version 1.0, which grew into a community supported initiative that saw adoption and provided for a solid learning platform. The team used Version 1 to test out the fundamental ideas behind the API, and then iterated with Version 2, which made some major breaking changes, including explicit versioning, the introduction of namespacing for forwards compatibility, and a restructure of the internals. Version 2 also led to the infrastructure
Source: https://managewp.org/articles/13568/rest-api-merge-proposal-part-2-content-api

source https://williechiu40.wordpress.com/2016/10/08/rest-api-merge-proposal-part-2-content-api/