Offensive and defensive security stuff focus on linux environment.
Virtualization
Learn how to use file storage in Staas services. In file storage we create a file and use it as our virtual partition then format it in desire file system and mount it. All the operation we do in our real disk partition(/dev/sda*) can be done on that with some little tricks or manipulation.
Tutorial
Information about files content can be found using different methods in both windows and linux systems. This knowledge can be handy if you are developing a program or script that is dealing with files.
Linux
Grub2 have the capability to boot directly from iso file present in any of your hard drive storage. Using this feature most Linux distributions as well as popular rescue CDs can be booted directly from an ISO file.