An Execution Environment refers to the context in which a program or application runs. It includes the hardware and software resources available, such as the operating system, libraries, and runtime systems. This environment ensures that the program can access the necessary resources to function correctly. Different types of execution environments exist, such as local environments on a personal computer or cloud-based environments like Amazon Web Services or Microsoft Azure. Each environment may have specific configurations and limitations that affect how applications perform and interact with other systems.