Diskless computer (DC) broadcasts MAC address with bootp: Who am I?
DHCP server on S looks up DB: Your IP address is X.X.X.X, your server is S, your boot file is vmlinuz.myname, etc.
DC asks to load file from TFTP server on S: Please give me vmlinuz.myname
S: Here you are (/tftpdir/vmlinuz.myname)
DC thinks a while (booting Linux).
DC: Please let me mount / with NFS
DC: Please let me mount other NFSes (/usr, /home/, etc)
S: Here you are
DC: Runs intended application
Network boot ROM contains code to do 1 and 3.