A composite part is a functional unit of DNA consisting of two or more basic parts assembled together. BBa_I13507 is an example of a composite part, consisting of an RBS, a protein coding region for a red fluorescent protein, and a terminator.
New composite BioBrick devices can be made by combining existing BioBrick Parts (like Inverters, Amplifiers, Smell Generators, Protein Balloon Generators, Senders, Receivers, Actuators, and so on).