What is Ubuntu Root Password

From debian, then instaling ubuntu.
First Install no Root password ask. using ubuntu with lxde desktop fine. problem come when instaling vbox.

Virtual box asked using root.
now where is root password, i never made it and by default now no password root for ubuntu.

for instaling an other sofware, sudo is fine. but vbox wanted root. and many other like instaling printer asked root user.

ok browsing and....

user can create root password.
just type

"sudo passwd root"

and fill the root password.

ok. hopely you are lucky find this post. and be free as root