Semantics of scalac -classpath

I’m reading the man page for scalac and the command line argument -classpath is not explained very well in my opinion.

I see the following description.

–classpath <path>
Specify where to find user class files (on Unix-based systems a colon-separated list of paths, on Windows-based systems, a semicolon-separate list of paths). This does not override the built-in ("boot") search path.

The default class path is the current directory. Setting the CLASSPATH variable or using the -classpath command-line option overrides that default, so if you want to include the current directory in the search path, you must include "." in the new settings.

The text fails to explain the semantics of the specified path. Is it a : separated list of directory names or rather is it a list of names of .jar files? If directories, then are they searched recursively or must I list all the directories explicitly in a directory hierarchy?