I agree with the existing answers & would like to back them with few relatable examples : 

**Archetype** :

Hero - Few common characteristics of heros are courage, selflessness, humility. 

Villain - Few common characteristics of villains are Intelligence , Powerful,
          Immoral 

**Personas** :

They share common characteristics but also have their own personal traits. Think of :

Heros: Batman & Harry Potter 

Villains: Joker & Voldemort

Think & compare their similarities & differences to understand importance of each persona within an archetype. 

**Archetype is a broad set of users based on common characteristics & Persona is a specific instance of an archetype.**