In plain words
A command is one typed request to the system.
Why learners confuse it
The terminal window, the shell, and the command all work together, so people often blur them into one idea.
A command is a text instruction you give to the system through a shell or terminal.
Beginners often treat commands as magic words. They are really requests to the system.
A command is a typed instruction that asks the computer to do a specific job.
A command is a typed instruction that tells the computer to do one thing.
A command is one typed request to the system.
The terminal window, the shell, and the command all work together, so people often blur them into one idea.
Study the larger concept after the word itself becomes clear.