Sometimes, it is important to show feasibility of a project before it is fully realized. The process for this is called a proof-of-concept, meaning an attempt to illustrate the practical potential of a concept or a theory. A proof-of-concept prototype is mostly a small — but sufficient — executed part of the full project. In science, proof-of-concept studies are small-scale studies designed to find preliminary evidence of some idea to gain financing for widening the research process. The proof-of-concept practice has been widely adopted by the filmmaking industry, engineering and security companies, software development, drug development and other fields of work. Sometimes the term “proof-of-principle” is used as a proof-of-concept synonym. However, the usage of this term comes from drug development studies where different meanings are attributed to both terms and varies from author to author.