Final answer:
The TSO command TERM is used to set terminal characteristics and preferences for interacting with the TSO environment on mainframe systems.
Step-by-step explanation:
The TSO command used to inform the system how you want to use your terminal is called TERM. This command allows you to set terminal characteristics and preferences such as the type of terminal, the screen size, and other operating parameters relevant to the interaction with TSO (Time Sharing Option) environment on mainframe systems. For example, to specify that you are using a 3278 model 2 terminal you might enter TERM 3278-2.
It's essential to set the terminal settings correctly to avoid mismatches in communication between the user's terminal and mainframe applications. This is particularly true in environments where multiple types of terminals are in use or where terminal emulation software is being used to connect to the mainframe.