A business application could be defined as a domain-specific solution (built with selected frameworks and capabilities) that solves a particular business problem. JBPM is typically used to build business applications.
It does not mandate any of the frameworks to be used, it can be successfully used in JBPM can be used as standalone service or embedded in custom service. It provides various capabilities that simplify and externalize business logic into reusable assets such as cases, processes, decision tables and more.
JBPM originates from BPM (Business Process Management) but it has evolved to enable users to pick their own path in business automation. JBPM is a toolkit for building business applications to help automate business processes and decisions.