A standard defined for dealing with medical imaging information. It includes a file format definition and a network communications protocol.
The communication protocol is an application protocol that uses TCP/IP to communicate between systems.
Entities that are capable of receiving image and patient data in DICOM format can exchange information between each-other.
Each DICOM service is based on two way communication. One is provider and the other is user, i.e. SCP & SCU.
SCP stands for Service Class Provider: The role played by a DICOM Application Entity which performs Operations (Response) and invokes notifications on a specific Association. This is a server from the network communication point of view. SCU stands for Service Class User: The role played by a DICOM Application which invokes Operations (Query) and performs notifications (Acknowledgement) on a specific Association. This is a client from the network communication point of view.