The "path" command allows the user to specify a command search path. The path is stored in the $PATH shell variable. Directories are separated by ":", and paths are separated by "/". A single ":" may be used to specify the current directory, as in "path :/this:is:path:two" .
Any variables used in the path are evaluated when you issue the path command. In the command "path $HOME:bin", the value of $HOME is evaluated immediately. If you change the value of $HOME later, the path will continue to point to the original :bin directory.