I have a set of linux installation disc , but I would like to know what is the difference of linux server and client , do they have different set of installation disc ? thx

The difference is the applications installed. A desktop probably doesn't want apache installed, and a server probably doesn't want a dvd player. Typically a distro will come with the lot, and aony install what's required for the desired use

A server installation may contain administration tools that the distro wrote for handling servers. It will probably offer a stack of applications, and may help set up things like ldap. Memory fails but there may be other differences in the scheduler and/or the filesystem. Somewhere, I I think I had a choice between server, workstation, desktop or media server.

Another important difference is in how the system is partitioned. A web server will have a large /var and /srv partition. For a desktop, they won't be on their own partitions. A server will have a separate partition for /tmp, which will be mounted with the "nosuid,nodev" options. A desktop system will probably have /boot,/, and /home partitions. A desktop will most likely be powered down, maybe abruptly, so the installation will probably use the ext3 or reiserfs filesystems. A server may use a more efficient filesystem such as xfs or jfs.