A process application is a container for process models and their supporting implementations; it is stored in the repository. After the artifacts have been authored or otherwise created, they are assembled into a process application.
You can use playback sessions to instantly test and manage the current working version of the process application (called the tip). You can also take a snapshot, which records the state of library items within a process application or track at a specific point in time. You can test, install, and administer a process application snapshot.
When it is installed, each process application has a business level application (BLA), which acts as a container for the process application and its assets (assets include things like monitor models, SCA modules, toolkits, and libraries). In addition, each snapshot of a process application has its own BLA. Many of the administration tasks for a snapshot (for example, stopping or starting it on a production server) are done at the level of the BLA, allowing for quicker and simpler administration of the snapshot and all of its assets.