apt-get update && apt-get upgrade
Unfortunately, oftentimes you need root permissions to do that. So a person will usually simply type:
sudo apt-get update && apt-get upgrade
And if you hit enter, "apt-get update" will run successfully and "apt-get upgrade" will fail. This is do to the fact that when you hit enter, bash has to interpret the line you just submitted. And according to the rules of bash, your line was interpreted to mean three things. First run "sudo apt-get update" then if that returns an execution code of 0, then continue to "apt-get upgrade".
What you want to do is send your WHOLE line to sudo for execution. You do this with the "-s" argument of sudo. so that:
sudo -s 'apt-get update && apt-get upgrade'
Of course my short way is usually simply typing "sudo !!" after i mess up the line, it works just fine.