Objects can be Mutable or immutable.
Mutable objects value can be chagned , whereas immutable object value can't be changed. Identities remain same for mutable objects but changes for immutable objects.
Mutable and immutable object and id()
For mutable objects by changing the element the id() value will not change , whereas for immutable objects id() value will change. List is a mutable object but tuple is a immutable object.