The host is used by the developer to (cross-)compile the code that will run on the target, for example a DAVE ARM platform such as Qong or Zefeer, while the host is assumed to be a PC running the Linux operating system. The Linux kernel running on the target is able to mount the root file system from different physical media. During the software development, it is very common to use a directory exported via [[W:Network File System|NFS ]] by the host for this purpose. Moreover, the linux kernel is usually retrieved by a simple network transfer protocol like [http://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocol tftp].