The terms wedding planner/wedding coordinator/wedding designer are often thrown around leaving confusion in the definitions. While there is some overlap, the roles tend to be very different!
Wedding Planner -
A wedding planner is there with you from day one to help the wedding evolve from beginning to end! They meet with you to establish your budget (and keep you on track), help you find your venue(s), offer recommendations on wedding professionals (photographers, caterers, bakers, etc.) that fit within your budget and particular style, they attend all vendor meetings, review contracts, negotiate rates, assist in creating the design and decor concept and, on wedding day, they set-up, coordinate the events of the wedding and they break it all down when it's over... In a sense, the wedding planner is the "producer of the wedding." Their scope of services typically will encompass both of the roles listed below. The fee for a wedding planner tends to be the highest on the scale of services because the work is very involved.
Wedding Coordinator -
A wedding coordinator can begin working with you at the beginning of your planning (suggested) to guide you through the process but usually does not attend the vendor meetings or become nearly as involved as a wedding planner. Many times, the couple will do all of the planning themselves and then meet with a coordinator within the last few weeks before the wedding to pull everything together. The role of a coordinator is to ensure that you have planned well, that your vendors are lined up and ready to go and they help create your wedding day itinerary and direct the rehearsal, ceremony and reception. The wedding coordinator can be thought of as the "director of the wedding." The fee for a wedding coordinator tends to be much less than that of a planner because their work is less involved and really only for the last month of the planning process.
Wedding Designer -
A wedding designer will help create "the look" of the wedding. They create the visual aspects and vision of the bride and groom based on their style and particular tastes for the wedding. Generally, they are working with florists and rental vendors to find the perfect aisle decor for the ceremony, centerpieces for the reception, lighting for the dance floor, etc!