• A dialogue is a small window that asks the user to make a choice or enter more information. A dialogue does not take up the entire screen and is typically used for modal events in which users must take action before proceeding.
• AlertDialog-A dialogue with a title, up to three buttons, a list of selectable items, or a custom layout can be displayed.
• Date Picker Dialog and Time Picker Dialog are two different types of dialogues.
• A dialogue having a pre-defined user interface for selecting a date or time.
• The Alert Dialog class is generally the only dialogue class you'll need because it lets you to create a variety of dialogue designs.

Read More: What language is used to write the Android operating system?