what are the types of event to use in Salesforce lightning component?

Event-driven programming is used in many languages and frameworks, such as JavaScript and Java Swing. The idea is that you write handlers that respond to interface events as they occur.
A component registers that it may fire an event in its markup. Events are fired from JavaScript controller actions that are typically triggered by a user interacting with the user interface.

There are two types of events in the framework:

Component events are handled by the component itself or a component that instantiates or contains the component.
Application events are handled by all components that are listening to the event. These events are essentially a traditional publish-subscribe model.