INverter!!
Charge pumps are quite a bit different than voltage doublers or multipliers using caps, however there are similarities. The standard voltage doubler uses an AC driving waveform and diodes to stack the peak AC voltage on top of each other.
Charge pumps use a DC input voltage. Internal to the charge pumps are switches that connect the capacitors in different configurations. The switches are electronically controlled by an internal state machine to close for particular lengths of time and in a particular sequence. Basically, they are transferring some of the charge in one cap to another. By arranging the switches and controlling their timing, it is possible to get a higher, lower or opposite polarity output voltage. The main drawback of charge pumps is the output current. It is not very high. A few tens of mA is easy. Above that level, charge pumps are difficult. They are a very good fit for small current applications like a couple of op-amps, or providing bias to an LCD, etc.
Look at the links in the previous posts, the block diagrams show the switches and you can trace the operation from there. You need not worry about the timing or closing order of the switches as the IC designer has already taken care of this for you.