Wiring two or more devices together in a circuit can be done in a variety of ways. The two most common ways are to wire the devices in a series circuit or as a parallel circuit. Whether the devices are in a series or a parallel arrangement affects the properties that the circuit would exhibit.
 

Series Circuits are characterized by a single pathway from the + to the - terminal of the battery. The bulbs are arranged in a consecutive fashion such that any charge that passes through the first bulb will also pass through the second and the third bulb. As a charge passes through a bulb there will be a loss of electric pressure. We sometimes call it a voltage drop. Since charge passes through all three bulbs of a series circuit, there is a combined voltage drop resulting from each stepwise loss of voltage in each given bulb. The actual amount of voltage drop in a bulb is dependent upon the bulb's resistance (and the current, which is the same in each bulb). Bulbs of higher resistance cause higher voltage drops. 

Parallel circuits are quite different because the bulbs are all placed in an individual branch with each branch operating independent of the others. A charge making a loop around the circuit will only pass through a single bulb. The passage through that bulb results in a voltage drop that is equal to the voltage of the battery. And so regardless of which bulb a charge passes through, the voltage drop will always be the same amount - an amount equal to the battery's voltage. As such the voltage drop across any branch is not dependent upon the resistance of the bulb in that branch ... but only dependent upon the voltage rating of the battery.