Wedding Planner: Planners are hired to help plan EVERY aspect of the wedding/event.  They deal with the full logistical process of preparation over a period of time and which encompasses much more than merely directing a ceremony or orchestrating details on the day of the wedding. 

Day of Coordinator: Are not responsible for planning the wedding/event, instead they're responsible for coordinating the details for the day of and executing them. They oversee the wedding/event day and provide a “month-of coordination service" to help prepare to execute the details that have already been previously planned. This leaves you to pick your vendors, set up the details that you want and is a more budget friendly option to full service wedding planner.

Venue Coordinator: Venue coordinators are employees of the venue and their one concern is the venue .  They are sometimes not even present the day of the wedding/event, and if they are its for a short time before the reception. When the venue coordinator tells you they can handle things on the day of your wedding, the scope is not what you think. They will be there for items pertaining specifically to the services the venue is offering. They will not set up your decor or make sure your vendors show up.