Difference between Ionic 2 & ionic 3

#1

What is big difference between ionic 2 and 3
can anyone explain me simply
and which is better pros and cons
thank you in advance

#2

ionic 2 and 3 is the same, the deference is version.
not like ionic 1 and ionic 2 , completely deference.

#3

3 is supported, 2 is obsolete.