instances

[Quenton Bonds]

Hello
I am trying to understand the abilities and limitation of creating an 
instance.  First I will give you my understanding then please steer me 
in the right direction.

Abiities
1.  The two ways to create an instance is def method(self) & 
__int__(self, other, instances,...)
2.  By creating an instance of a method; the functions of that method 
can be used through out the
   program in a fashion such as self.methodofprogram(parameters)
Limitations
3.  One cannot create an instance of a class.
4.  An instance can only perform functions that are provided from the 
method it was instanced from.

5.  Is there any other key information I am missing.