The Free On-line Dictionary of Computing (30 December 2018):

static method

    In object-oriented programming, a function
   packaged along with a given class; not really a method at all.

   For example, a String class might include a static method,
   concatenate(), which returns its arguments joined into one
   string.  It might be called like this:

    print String.concatenate("FOL", "DOC");

   which would print "FOLDOC".

   The same result might be achieved with a real object method,
   append(), which returns its argument string appended to the object
   it is invoked on, e.g.:

    String s = "FOL";
    print s.append("DOC");

   While the syntax looks similar, the two are completely
   different.  The static method is just a function called
   "String.concatenate" which can be resolved to the address of some
   code at compile time (or load time if the String class is
   dynamically loaded).  When invoking an object method, the class of
   the object is not generally known until run time so method
   lookup is a run-time process.

   (2014-09-06)