Power to Switch First: Here, the power comes into the first switch box, then runs to the light fixture, and finally to the second switch. This is typical when the power source is closer to the location of one of the switches.
Power to Light Fixture First: In this arrangement, the power source comes into the light fixture box first and then runs to the switches. This is a common setup when the power source is located near the light fixture in the ceiling.
Light Fixture at the End: In this configuration, the power source runs from switch to switch before going to the light. This is often found in setups where the light fixture is not between the switches but rather at the end of the circuit.