Originally Posted By: Bob_00001
Question: Is a dmg compressed?
(I assume it is. Otherwise, why would it be the method of choice for distributing software online.)

A .dmg MAY or may not be compressed. It may also be encrypted if desired.

Originally Posted By: Bob_00001
Question 2: What is a sparse disk image, and what is a sparse bundle disk image?

A sparse disk image is a form of disk image file that can grow or shrink depending on the size of the files contained within the image.

A sparse disk bundle is a directory containing a number of files or bands, each a fixed size (8.4MB in OS X 10.8) that makes it possible for Time Machine to more efficiently manage its data.


"All you've got to do is own up to your ignorance
honestly, and you'll find people who are eager to
fill your head with information"
--Walt Disney