You really should not consider LAN booting or disk management setups if the basic concepts are too difficult.
PXE is simply a pre-boot environment that allows booting (including reformatting and system installation) over a local area network. It is built into the bios and is called something like network boot, LAN boot, PXE boot, or the like. When started up, the computer "looks for" a server on the network to boot from instead of one of the local devices (cd, HDD). This is the simplest tutorial that I found: http://www.howtogeek.com/57601/what-is-network-booting-pxe-and-how-can-you-use-it/