How do the dependency paths work in Java .classpath file?

Question

In the Java .classpath file, I see a lot of dependency paths, something like this:

<classpathentry kind="lib" path="/a/b/c/d/library.jar"/>

Are these paths absolute to local file system, or are they relative to some project folders?

Without using tools like Maven, how can multiple developers work on the same project sharing the same .classpath if they have different dependency repo location? If different developers of the same project work on different OS, like Windows and Linux, would these paths still work? Say for windows, can I have a path absolute to my file system (e.g. C:\my_repo...)? Would that break something for the Linux developers if we share the same .classpath file?

And if I pass the project to someone else to continue to work on, how can that person get those dependency jar files back on their local repo without downloading those jars one by one manually from the Internet/Maven central? (Without using Maven, that is...)