An Application Entity (AE) is a functional component in a system that is a user and/or provider (SCU/SCP) of one or more DICOM services. Each AE uses a unique AE Title to identify itself.
Devices often have a different AE for each DICOM service. For example, a modality might incorporate one AE for DICOM Storage, and another for DICOM Modality Worklist.
The relationship of a device's AEs to real-world activities is graphically represented in an application data flow diagram (also commonly called a bubble diagram). This diagram is found in the DICOM conformance statement for a given device.