Execution models are frameworks that define how tasks and processes are carried out in computing systems. They help in organizing the flow of operations, determining how resources are allocated, and managing the execution of programs. Common execution models include sequential execution, where tasks are performed one after another, and parallel execution, where multiple tasks are processed simultaneously to improve efficiency. Different execution models can be applied in various contexts, such as distributed systems and real-time systems. Each model has its advantages and challenges, influencing performance, scalability, and responsiveness. Understanding these models is essential for optimizing software and hardware interactions.