Print Head Alignment

[ACM]

What does aligning the print head in a bubble-jet printer actually do? Apart from making the picture better and lines straighter, how does it actually work? Some technical information would be appreciated.

[glc]

Without knowing exactly what it does, I would guess that it's similar to aligning the convergence in a monitor or TV - getting all 4 colors to shoot in the same place and in synchronization.