Angular JS (1.x) is a javascript based framework developed by google. It simplifies the UI development by abstracting the low level coding. Some features of Angulas JS (1.x) is two way binding (data+UI), directives,form-validations,components etc . Referred as MV* UI framework.
Angular 2 was released sometime after Mid 2016 and is not backward compatible and is based on typescript.
More info : https://angularjs.org/