The DEVELOPMENT stage of an Electronic Products task might include developing the circuit using 'Euro-board' and making sure that the output effect was exactly what was required. These stages may be used later in the earliest PROTOTYPE models.  A similar stage in a Food task might be to explore subtle changes in the texture of a particular chosen food product by altering the size of pieces of one ingredient- whilst a Textiles technology project development section might involve experimenting with the lie of a fabric given that a particular fastening had been decided on.  So Development really means improving and improving on the chosen idea - its all about details.