Google's Angular is a massively popular MV* JavaScript framework for building complex modern applications, be that for the web, mobile, or desktop. It comes with nearly everything you need to build complicated frontend apps, including powerful templates with fast rendering, data management, HTTP services, form handling, routing, modules, and more.

Historically, Google launched the first version, toward the end of 2010, of what they were proud to present as the best framework for SPA: AngularJS. The AngularJS framework relates to the former incarnation of today's Angular, which was given version numbers of 1.x. Interestingly, AngularJS is still quite active and continues to be updated. 

Later, Google decided that AngularJS was not on par with recent progress made in the field of web UI development. Its structure and the way it was built made it difficult to improve its performance and design to meet future standards. Therefore, Google announced that they had been working on the successor to AngularJS, which was Angular. Confusingly, readers should note that while there are similarities in the high-level building blocks, these are actually two completely separate frameworks.

By the end of 2016, Google released its new Angular framework. Angular is a vast framework that provides a complete toolset intended to allow developers to build complete modern apps. This notion alone was met with quite a bit of controversy. On one hand, there are many developers who love the fact that they're handed nearly everything they need to build apps from start to finish. On the other hand, others tend to prefer the flexibility and freedom to employ their own formulation of toolsets for different parts of their applications.