I don't understand what a linux command means. Please explain it.

curl https://packages.gitlab.com/g. 2 > / dev/null | sudo apt-key add-& > / dev/null

I don"t know what this statement means. There are numbers > null & >-what all these stand for


redirect. Redirect stderr to / dev/null and redirect what is supposed to be displayed on the screen to an empty device, which means shut up and don't force printing on the screen.

reference: https://blog.csdn.net/long274.