Select Slackware installation source:

1. CD or DVD drive.
2. Hard drive partition.
3. Network File System (NFS).
4. FTP/HTTP server.
5. Pre-mounted directory.

If this is your first time installing Slackware, probably you already used DVD installation source. As you can see from the list, Slackware supported many methods of installation. Next time you want to install Linux, maybe you can plan to used different methods, for example, using NFS to install Linux in several computers in local network.