Everything running on your device is a process with an id. Being able to list them and stop the right one is the difference between a stuck terminal and a working one.
Each one is marked as you go, and the explanation arrives straight after, which is
the part worth reading.
4 questions, marked as you go.
Tasks
These need your own device. Run the command in Termux, then paste what it printed.
The marking looks at what the output means, so spacing, version numbers and
ordering do not matter. If you have not installed anything yet, the
lesson covers the setup.
List what is running
This lists the processes your account can see, with the command that started each one.
Run this in Termux
On your own device. Nothing on this page executes it. The command runs in
your terminal, and this box only reads what you paste back.
ps
The first line is a header naming the columns, not a process.
the output has a header naming the columns
at least one process row, starting with its id
a header and at least one process
What a good answer looks like
A header line naming the columns, then one row per process. The columns you will see are a process id, the terminal it is attached to, the processor time it has used, and the command. The command column is the one to look at, because it shows exactly what was typed to start each process, arguments and all. That visibility is the reason a password should never be passed on a command line.
Marking your own work
Both halves of this are checked in your browser, with no server involved, so nothing
stops you from pasting output you did not run. The tasks are written so that the
easiest way to pass one is to actually do it and read the result, which is the whole
intention.