Distinction between Molecularity and order of reaction?

Molecularity is the number of reacting species undergoing simultaneous collisions in the elementary or simple reaction.

* Molecularity is a the orietical concept.

* Molecularity has whole number values only like 1,2,3----

* It can’t be zero for any reaction.

* Order is the sum of the powers of the concentration terms in the rate law expression.

* It is determined experimentally.

* Order of a reaction need not to be a whole number. It can also have fractional values

* Order of a reaction can be zero.