- Snippet from Wikipedia: Network booting
Network booting, shortened netboot, is the process of booting a computer from a network rather than a local drive. This method of booting can be used by routers, diskless workstations and centrally managed computers (thin clients) such as public computers at libraries and schools.
Network booting can be used to centralize management of disk storage, which supporters claim can result in reduced capital and maintenance costs. It can also be used in cluster computing, in which nodes may not have local disks.
In the late 1980s/early 1990s, network boot was used to save the expense of a disk drive, because a decently sized harddisk would still cost thousands of dollars, often equaling the price of the CPU.
You set up a TFTP and a DHCP (or BOOTP, or RARP) server which will serve the installation media to machines on your local network. If your client machine's BIOS supports it, you can then boot the Debian installation system from the network (using PXE and TFTP), and proceed with installing the rest of Debian from the network.
Not all machines support booting from the network. Because of the additional work required, this method for installing Debian is not recommended for novice users.
For details, please refer to the installation manual for your architecture, especially the chapter “Preparing Files for TFTP Net Booting”.