Ok, here's how it works simplified:

lift, how far the lobe rises off the base circle, multiply that by the rocker ratio and you get valve lift, what most cams are advertised at.
Basically the more the better at the expense of parts life. Also every head has a max lift that if they surpass flow will actually be reduced. Most stock performance SBC's it's between 480" and 510" lift optimum.

Duration, how long the valve stays open. the longer the higher RPM the engine can turn. It creates overlap and poor efficiency at lower rpms. Gives that "rough choppy" idle.
It is measured at different amounts of lift, advertised can be .002"-.006" lift, and there's duration@50 or at .050" valve lift{more accurate}

LSA, or Lobe Seperation angle. It lets you know the basic powerband the cam will have. A tight LSA 104will have a rough choppy idle from the extra overlap, reduce the bottom end power, peak really strong in the midrang and fall off on the top end {keep in mind that this "powerband" is not the RPM of the engine, which it determined by the duration}
A wide LSA 114 is more efficient due to less overlap. It will have better bottom end, not much peak power, and good top end. They result in a wide, flat torque curve.
Also they are good for blower motors and Nitrous b/c the exhaust doesn't react with the fresh intake mix as much.

If you have a low compression engine a wide LSA can help it build cylinder pressure and if you have too much compression a tight LSA will help bleed some off {generally speaking}.