What is the difference between posting an event Public vs. Private?

Posting an event as Public will allow all Freelancers too see event and make an offer if they are interested. Once an event is set as Public, Hiring Managers can not change to Private. 

Posting an event as Private will only allow Hiring Managers to invite specific Freelancers they are interested in. An event can be changed to Public from Private if more Freelancers are needed.