This entity is used when you want to show the external entity in your data flow diagram. The external entity can be anything which is external to your system, for example, the users, computers, any other system, and so on. The symbol used to represent the external entity is square with rounded corners.

External entity is used to show how the external entity is related to the data flow. For example, the user is an external entity who gives input and is shown accordingly in DFD.