Berlo's S-M-C-R Model proposes that communication involves five main elements: the Source, the Message, the Channel, the Receiver, and their relationship. It emphasizes that both the source and receiver influence the communication process through their individual communication skills, knowledge, attitudes, and socio-cultural backgrounds. The source encodes a message using a particular code, content, and treatment, which is then decoded by the receiver based on their own characteristics. The success of the communication depends on both the source and receiver, as well as the complex relationship between them.