A single hard disk drive can store multiple operating systems. While different versions of Microsoft Windows can co-exist on the same partition, other OSs, such as Linux and FreeBSD, need their own partitions. We’ll understand the necessity later on when we discuss file systems.
The ability to multi-boot is very useful, as one single computer can then be used to run different OSs. Under a normal multi-boot method, the various OSs must run exclusively. However, virtual machines (VMs) now permit the use of multiple OSs in parallel. Most VM engines, call emulators, can utilize nature partitions to maximize efficiency, making partitions a very useful mechanism even with modern VM technology.