PATH is an environment variable that will list the directories to search for a command (script or binary).
echo $PATH on a terminal will output your current PATH variable.
Usually, the terminal recognizes directories called "bin" in the user home and add it to the PATH (this is done automatically when the ~/.profile script is called by the terminal on invocation).
So what this instruction is telling you to do, is to create a symlink to your program on the ~/bin folder, if that exists (or creating it and including the symlink if it doesn't).
ln -s path/to/your/program programname
Then you can call your program by just typing its name in the terminal.