Pipes are one of the most useful Linux ideas. They let small commands work together.
Try these commands
ls -lah | grep pdf
df -h | grep DATA
echo 'hello' > test.txt
cat test.txt
Tip: Start by reading the command. Then predict what it will do before pressing Enter.
Safety: Never paste a command you do not understand when it contains
sudo, rm, disk/partition commands, or redirects to important files.