• Dynamic Typing
• variables as Object references

<note important> function subroutine executed independandly
method function bound to an instance of an object
operator function bound or not to instance, do not use parenthesis and part </note>

• comparison opérator == , < … =⇒ Value comparison
• is operator =⇒ identity comparison (identify of an object can be retriece by object.id())
• None special null object (singleton)