An example of an absolute path to bar.exe, "c:\foo\bar\bar.exe"
An example of a relative path to bar.exe starting at c:\foo\foo, "..\bar\bar.exe"
So basically an absolute path starts at the root and works from anywhere, vs a relative path which is always relative.
Occasionally a port doesn't understand drive letters so as long as it is on the same volume, "\foo\bar\bar.exe" will also work
Sometimes ports want / as a path separator instead of \ as well or they see \ as an escape character, in which case \\ will work.
You'll need to test