Sparse image or sparse bundle?

[techno]

The size of my MacBook's internal hard drive is always changing since I frequently take files on and off. I love the idea of a disk image backup that grows or shrinks with a Smart Update to accommodate any changes. I can't seem to see the difference between a sparse image and a sparse bundle. What should I use to backup my MacBook with Snow Leopard?

[dnanian]

The backup image won't generally shrink, although it will grow... a sparse bundle is a collection of separate 'band' files, each of which is smaller than the whole drive, whereas a sparse image is one big file.

[techno]

So I take it that it depends on the individual user's situation to say which one is better? Any general suggestion for a casual user making a complete backup on an external drive who runs Smart Update maybe once a week?

[dnanian]

In general, on Leopard and Snow Leopard, use a Sparse Bundle... note, though, that some NAS devices don't support Sparse Bundles, and thus you'll need to use sparse images.