The first is Simply Filling (also know as Filling and Healthy, and I think this is the old Core plan) where you eat the foods from a specific list. All fruit and veg are free plus (I think!) pulses, lean meats, fish, etc. There's a list on the website that you can download. You don't need to count points for anything that comes off that list or is fruit or veg and you also get two teaspoons of oil free each day.
The other plan is Propoints, this is where the 28 propoints (pp) comes from. You have 28pp each day and you need to point everything apart from most fruit and veg (there are a few exceptions like parsnips). In case anyone reads this as reference in future - the number of propoints you're allowed depends on your gender, height, weight, if you're breastfeeding or not... it's specific to your situation and will go down as you lose weight.
Then, no matter which of those two you choose, you have 49 pp per week to spend on eating out, wine, chocolate, etc. If you're on the simply filling plan, anything you eat that isn't on that list comes from this allowance (so if you fancied a bit of white bread instead of wholemeal, that would come from these 49).
