Angular is a framework that you can use to build applications using HTML and JavaScript/TypeScript.

Some call it a web framework as a result.

Using Angular will involve accessing the various libraries that make up the framework.

As the documentation on angular.io indicates,

"You write Angular applications by

• composing HTML templates with Angularized markup, 
• writing component classes to manage those templates, 
• adding application logic in services, and 
• boxing components and services in modules. 

Then you launch the app by bootstrapping the root module.

Angular takes over,

• presenting your application content in a browser and
• responding to user interactions according to the instructions you've provided."

If you were asked to explain Angular in a nutshell, you might say that it is a framework that simplifies the creation of

• rich,
• interactive,
• client-side 

web applications, using data binding.