Definition:
A proof of concept (POC) is a demonstration, the purpose of which is to verify that certain concepts or theories have the potential for real-world application. POC is therefore a prototype that is designed to determine feasibility, but does not represent deliverables.
Proof of concept is a term with various interpretations in different areas. POC in software development describes distinct processes with different objectives and participant roles. POC may also refer to partial solutions involving a small number of users acting in business roles to establish whether a system satisfies certain requirements. The overall objective of POC is to find solutions to technical problems, such as how systems can be integrated or throughput can be achieved through a given configuration.
Further Reading:
Book: Applying UML and Patterns by Craig Larman
