The shell reads a startup file before it gives you a prompt. Editing that file is how you keep your aliases, your prompt and your PATH across sessions instead of retyping them every time.
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.
Set an alias and show the search path
This sets a short name for a long command, lists the aliases in the shell, then prints the folders the shell searches for commands.
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.
alias ll='ls -l'; alias; echo $PATH
The alias line proves the alias exists. The line after it is one long string with colons in it.
the alias you set is listed
the search path is printed as an absolute path
the search path includes the system program folders
the commands actually ran
What a good answer looks like
The first line is the alias you set, shown as alias ll= followed by the command it stands for. Then a line listing any other aliases the shell already has. The last line is your PATH: several folder names joined by colons, searched from left to right. The exact folders are personal to your setup, so read the shape and the order rather than expecting particular paths.
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.