What is a key feature of the mainframe/terminal network model?

In the mainframe/terminal network model, a key feature is that a mainframe computer runs all programs directly on the mainframe itself. This model centralizes computing power, meaning that the terminal devices function primarily as input/output devices that communicate with the mainframe. The terminals do not have the capability to execute programs independently; rather, they rely on the mainframe to handle all processing tasks. This design allows for efficient management of resources, as the mainframe can oversee and control all aspects of the programs being executed, making it easier to maintain and update software without needing to manage individual terminals.

In contrast, the other choices imply functionalities that do not align with the centralized nature of this model. While terminals may input data and display results, they do not run independent programs or perform data processing on their own, nor do they operate without a connection to the mainframe for processing tasks.