What is the difference between a Java API and a library?

Question

I know that an API is called a set of functions used to call something, and a library is a collection of classes, but what is actually API in package like java.lang

Answer 1

In object-oriented programming , a class library is a collection of prewritten class es or coded templates, any of which can be specified and used by a programmer when developing an application program. you could use a library in a variety of projects. A framework is a collection of patterns and libraries to help with building an application. An API is an interface for other programs to interact with your program without having direct access.