Although I have been using ubuntu for about two months, I never really
understood how things are installed in ubuntu. But, I just formatted my hard
drive and reinstalled everything with ubuntu 10.04. This time, I want to
understand everything how ubuntu works, so, I can have a better control of my
pc.

In windows, most file for any specific software are contained in a specific
folder (.exe, .dll files etc). But, this is not the case in ubuntu.

Instead, I have noticed the following:
/bin
binaries
- commands for the shell
/dev
device files - hardware
/etc
config
files
/lib
libraries
/sbin
binaries that the system use ............and so on.

Moreover, there is a bin folder in other sub-folders. why is that?

For example, if I run flashplayer.deb file through terminal and install
flashplayer plugin, where will the installation file go?

Apologies, if I have make this question over complicated. Thank you for your
considerations and hope to hear from you soon.