Linux

i used puppylinux(only 95mb) good OS.i have some doubts raised
1.)how a bootable drive is different from a unbootable drive(drive=a harddisk or pendrive or a cd etc..)?
2.)how puppylinux is able to play sounds without audiodriver installation (which is needed in windows)?

Your questions seem odd or vague.

A bootable drive has a bootable image/kernel on it. As long as your firmware can map to it, you can boot from it should it have the proper files.

Puppy linux DOES have drivers for audio. Otherwise it would not be able to play audio. Linux does not work like windows. The drivers can be loaded into memory for generic devices and address them via alsa or something else like it.

Linux has drivers for alot of hardware.
and i mean alot.
the drivers are part of the kernel.
you can even make them INTO the kernel binary, or compile them to a module and load it at runtime

about the bootable part, as mark said, depends on your bios ability to map things out.
some bios can boot from usb disks
the most important difference here is if you use a writable medium or not.