Loop devices on Linux are virtual devices which can be used to mount files like real devices. For historical reasons you have 8 such loop devices by default, but in current Kernel releases you can of course use more than just 8.
Processes are a very complex but important topic for understanding how Linux works. Covering all details about process management in Linux wouldn't be possible for one blog post, but let's have a bit of informative fun with process creation and especially with their deletion. It's Halloween and which topic could be more appropriate than birth, death and undeads?
When you freshly set up a Linux distribution by hand, you get a lot of verbose output when booting into your system, but also install'n'go distributions like Ubuntu oder SUSE output some text when loading the kernel. This is not always desired and many people want to suppress these insistent system messages, but it's not as easy as you might think.