DAEMON Tools Pro Advanced is a comprehensive suite of tools to help you work with optical discs.
The program can back up your CDs, DVDs or Blu-ray media, for instance. It's able to create ISO, MDS/ MDF or MDX image files, perhaps compressing them to save space. And you can password-protect them for additional security.
You're also able to manually create disc images, when necessary. You get plenty of low-level control options, so for instance it's possible to choose your preferred file system (ISO9660, ISO9660+Joliet, UDF), or create bootable discs, and of course if you need a physical copy then you can also burn these images to disc.
Perhaps DAEMON Tools best-known feature, though, is its ability to emulate optical drives. It can then mount images in all the main formats - *.mdx, *.mds/*.mdf, *.iso, *.b5t, *.b6t, *.bwt, *.ccd, *.cdi, *.bin/*.cue, *.ape/*.cue, *.nrg, *.pdi, *.isz - to those drives, allowing you to access their contents without forever having to swap physical discs around.
There's a lot of power here, then, but DAEMON Tools Pro Advanced provides many ways to access its various features. You can work through the main program interface, for instance, or via a handy desktop gadget. Shell integration allows you to carry out several functions from the Explorer context menu, and there's even a command line interface to help you automate common tasks.
Please note, this is the high-end version of DAEMON Tools; if you don't need all of its features, then there are other editions which might be more suitable. Check the product comparison page to find out more.