Explain component decorators in Angular4.

A decorator is the core concept when developing an angular framework with version 2 and above. It may become a core language feature for JavaScript soon. In angular 4, decorators are used extensively and are also used to compile a code. There are 4 different types of decorators:

• Class decorators
• Property decorators
• Method decorators
• Parameter decorators

A decorator is a function that is invoked with a prefixed “@” symbol and is immediately followed by a class, parameter, method, or property. A decorator returns the same thing which was given as an input but in an augmented form.