Orchestrations refer to the business process workflows and logic implemented using Microsoft BizTalk Server for coordinating and automating integration activities across multiple systems, applications, and services. Orchestrations define the sequence of steps, activities, and actions required to execute business processes, handle exceptions, manage transactions, and interact with external systems. Orchestrations use visual design tools or declarative programming models to define workflow logic, message routing, error handling, and state management to orchestrate complex integration scenarios efficiently.