Materials: The actual substance from which the presentation and or design process is composed og. This includes paper, cardboard, wood, clay, plasticine and or any other "materials" you use in the production of your final presentation, be it an illustration or a Model. this is also relevant to the materials you use in your folio progressions, but most of the time I guess that is simply limited to paper? you could always look at drawing on that yellow baking paper stuff (I did substantial work on that for my unit 4 folios) and or other grades of paper as well.
Media: The devices you use to make a mark or an imprint on your materials. So for example, colour pencils, crayons, INK (this is what you should use to refer to computer work and or ICT), whether the ink is inkjet or laser is also relevant in some cases. So any equipment you use to actually depict your illustration.
Methods: The techniques you use to apply your media to you materials. These include constructing techniques such as 3D model making, drawing techniques such as instrumental drawings and free-hand drawings. Actual artistic techniques such as burnishing, and or rendering with copics. most importantly is that this category houses the all important use of digitial software and the use of computer programs.