Why does Abigail accuse people of witchcraft? Who do the girls accuse? Why do they pick on these certain people?

All together 20 people were killed in the Crucible. 19 were hung and 1 (Giles Corey) was crushed by rocks. The girls accused many people, usually as a result of Abigail's manipulations. People like Giles Corey, Elizabeth Proctor, Rebecca Nurse, George Jacobs, Martha Corey and John Proctor are all targeted by Abigail and the girls. All of the accusations have to do with personal vendettas, deflection of blame or power plays within the village. Abigail is initially after Elizabeth Proctor. She wants to punish both Proctors after her failed affair with John Proctor. Mr. Putnam covets the land of George Jacobs. He gets his daughter to fabricate a story condemning George. When threatened with being exposed, the girls often accuse their critics, like John Proctor, of witchcraft as well.