Sudo su - sorry. What's wrong?

I’m studying this book Build Your Own Database Driven Web Site Using PHP & MySQL, 4th Edition - SitePoint Books . During installation, I am to enter “sudo su” in Terminal. It then asks for my password. I give it my password, and then it says “sorry”. If I try “sudo su” again, it just says “sorry”, until I log out and back in, and then the process is repeated. What is going wrong?

Thanks!

It either means you’re typing your password incorrectly, or you’re not allowed to sudo su.
I think it’s the first issue though, that what it usually says when you enter the wrong password.

sudo is a program that runs a command under a different user so it is normal it will ask the passord for that user ewhere you want to run the program with. If you don’t put the right password or if you don’t have enough rights with that user it will not work.
sudo - Wikipedia, the free encyclopedia