making sense of new generation of Linux

There are several ways to run Linux:
1) Install Linux from installation CD the traditional way
- need CD ROM drive
- need new partition in harddisk
- can only run one system at a time

2) Run Linux from Live DC.
- need CD ROM drive,
- don't need new harddisk partition though
- only can run one system at a time

3) Load Linux Live CD from virtual machine
- don't need CD ROM
- don't need new harddisk partition
- can easily switch between host OS and guest OS!
- file sharing locally could be issue, but can be overcome through IP applications!