The first one is what you're planning to use or what you're planning to do, the second is what you used and how you used it or what you ended up doing and how it was done.
You would not tackle this directly, these are things you would be keeping documentation of throughout your entire MDP, the 1st point will be a great deal of your Project Proposal and perhaps other parts, the 2nd point is going to be the majority of your Project Dev section, you would have alot of changes to idea's and realisations of a bad idea or non-feasible idea and you must justify why you chose to research a particular topic or why you chose this material or whatever, just about everything in this section should come with a conclusion, many or most of these things are going to be from the things you said you would look into in the Project Proposal. It would also tie in with your Evaluation section, the resources you used will effect your evaluation of impacts on society and environment and your money spending etc
It's like a progression, you first say what your plan is, then you have the documentation of doing all that and making decisions, then you finish with a final examination of the everything that took place. Everything should fit together, you should pretty much be able to stick a coloured dot next to a topic in your PP&M and then stick a same coloured dot to that topic in PD&R and another in Eval. The markers will be looking for this progression and the more obvisous you make it the more impressed they'll be.
Depending on how much of your MDP you've done, you should really have these points covered already as you are working through the MDP.
edit: If you would like an example incase my words are not clear enough, I'll post some of my MDP.
