I wonder when to use what flavour of Python 3 super().

Help on class super in module builtins:

class super(object)
 |  super() -> same as super(__class__, <first argument>)
 |  super(type) -> unbound super object
 |  super(type, obj) -> bound super object; requires isinstance(obj, type)
 |  super(type, type2) -> bound super object; requires issubclass(type2, type)

Until now I've used super() only without arguments and it worked as expected (by a Java developer).

Questions:

• What does "bound" mean in this context?
• What is the difference between bound and unbound super object?
• When to use super(type, obj) and when super(type, type2)?
• Would it be better to name the super class like in Mother.__init__(...)?