Alyssa, thanks for stopping by with your question. There can sometimes be a bit of confusion between the two, so hopefully I can offer some clarification.
Disney's PhotoPass+ is the premium option as it includes unlimited PhotoPass pictures, attraction and dining photos from select locations, a gallery CD with over 400 stock photos, and a PhotoCD of all your PhotoPass pictures (with and without edits), an lanyard/card. As you know from prior use, you can pre-order this for a discounted price as long as it is purchased 14 days prior to your arrival date. The PhotoCD is included in the cost of the PhotoPass+ package.
The standard PhotoPass is available to any and all guests who stop and have their photo taken by a PhotoPass photographer anywhere on Walt Disney World property. The photographer will hand the guest a PhotoPass card (standard PhotoPass does not have the lanyard) to use for the duration of their stay. There is no obligation to buy or view their photos. You may or may not have more than one card. Often, if my family separates during the day, we may get two or three different cards. These can all be added and viewed under one account once you return home. There is no pre-order for this service and no voucher is sent out.
If you would like to
pre-order a PhotoCD, there is a discounted rate for this (separate from PhotoPass+). Once you return home and input your PhotoPass card number(s), you will then enter a special code that should be emailed to you after your pre-order.
I hope I was able to make this a little easier to understand. Have a magical time and say CHEESE!
~Allison L