UNIX for Dummies Questions & Answers

Hi guys having some days with linux os i have found it to be very confusing (thanks to different flavors available).every time i face any problem i start analyzing it from windows point of view.
Here i m with one more query .

Unlike Window, Linux has different partitions naming policies.Most of the system data resides in / .Does this mean its similar to c: in windows system where all system data resides ? can we reinstall another flavor of linux by just formatting / ?

is it possible to dual boot two linux flavours in same machine just like we can dual boot two windows OS machine by installing one OS in c:drive and another in d: drive and making changes in boot.ini file?

One of the most important things to note: Linux is not Windows, and as such it's hard to compare the directory structure, naming, ...

When you say
you probably have only one partition for everything. While that's not wrong per se, it's possible (and for some deployments even suggested) to use different partitions for different directories. For example, one could use a / (root) partition for everything needed to boot, one partition for /usr (programs not necessarily needed for booting), another one for /home, ...
In Windows terms that would mean that C:\WINDOWS is on one partition, C:\PROGRAMS on a different one, C:\DOCUMENTS AND SETTINGS on yet another one, ...
Probably yes. If you have /home on a different partition, even all the users files and settings will survive.
Of course, and even easier than with Windows. Most current distributions can detect other Linux installations, and automagically adapt the boot loader to enable booting the previous installations. Newer Versions of GRUB will do this even when the boot menu is re-generated.