Rooting gives you (or an app) administrative access (the same as right-clicking a program in Windows and clicking Run as administrator).
It doesn't give you free apps, all it does is allow apps that need administrative access to run.
How it works ... well, how installing it works is that someone has to find some way to force that phone, or that kernel, to give it temporary administrative access so that it can install a file named su (for superuser) - which is what gives you root, and which you can't do unless you're already rooted. Sort of a Catch 21.5, since there's always going to be some bug or overlooked hole to use. (The problem is finding one little error in a few million lines of code, when you have no idea what you're looking for.)
If you go to Settings/General/About device and look at the kernel date, you may be lucky and find that it's before June 3, 2014. In that case,
Towel Root should root the phone. It's just an app you install, press the "make it rain" button and the phone gets rooted. If it's later than that, check the LG Volt sections of forums.
XDA Forums is always a good place to look for rooting programs and ROMS, and
http://androidforums.com/forums/lg-volt.2749/ is a Volt forum.