In short, it can tell you a lot of stuff. You could identify (probably) the following:
- Type of star E.g. a light curve of a eclipsing binary system
Light curve of supernova:
Not only that you can also identify the radius (thereafter volume), size of the planet, and the orbital period by measuring the elapsed time between transits.
You can identify quite a bit of information. Given you find orbital period, radius etc., you can use this information to find other information too. So it keeps branching!
Kepler's Third Law: the squares of the orbital periods of the planets are directly proportional to the cubes of the semi-major axes of their orbits. Kepler's Third Law implies that the period for a planet to orbit the Sun increases rapidly with the radius of its orbit.