At runtime a project consists of one or more threads, processes, functional units, and data units. These elements may run on the same computer or on multiple computers across a network. The same element in a code structure may implement or support multiple runtime elements.
For example, in a client-server application, the same client module may run on many client computers. Conversely, several code structure elements may implement or support a single runtime element. For example, many threads will run multiple methods from different classes that maybe packaged in different code units.