Path of Executable
This is the path that corresponds to the first part in a full command.
Executable can be either full path or just file name.
Example: gcc abc.c
The full path of an incomplete executable (gcc) is looked up in the path list defined by the environment variable PATH (defined in the .bashrc, .configure, system init scripts, etc).
Path of Arguments
Arguments (if it is a file in the file system) can be either full path or just file name.
If the argument is given by only a file name. The path is regarded as a relative path (relative to the current working directory). The full path is then generated to be used by the executable.