Execution Context

We run code by

• Defining objects
• Invoking methods

Every time we invoke a method, the Javascript engine creates a new execution context.

Global Execution Context

Even though we do not define any objects or methods, the Javascript created a Global Execution Context.

This global execution context provides a global object named window. In node.js world this global object is called global.

Global execution also provide the this context. Both, the this context and window object are the same object.

Also there are Hosting in the global execution section, used to run before the code execution.

Whenever we define a global object, it is attached to the window object by the global context.