The differences between PDP and CPD are more of timing than processes differences. PDP is an excellent preparation for Continuing Professional Development which also involves undertaking regular reflection, reviews, planning and actions to achieve specific goals. Students studying subjects such as Medicine, Nursing, Accountancy and Law will be aware of the importance of registration or recognition by the relevant professional body to their future career. Most professional bodies expect their members to demonstrate evidence of CPD and provide journals and courses to allow members to regularly refresh and update their knowledge and skills.
Even for those that will never experience CPD, most employers have an annual appraisal or similar process where they expect their employees to review job related goals from the previous year and agree goals for the year ahead.