What is the -y flag used to install apt-get?

Question

What does the flag do -yat startup apt-get install?

Example, from https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions :

sudo apt-get install -y nodejs

Answer 1

Skip installation confirmation when you install something, ubuntu always asks for confirmation (Y / N), with -y Ubuntu skips this part.