As the visual above indicates, assessment is an ongoing activity performed by both the learner and the instructor as a means of improving the skill and knowledge level of the learner, but also the instructor. The learner has feedback on what they are doing well and continue to need improvement on to be able to meet the outcomes of the course, and the instructor assesses the value of their learning materials and methods of instruction based on how well their students are learning and meeting those same outcomes.
Evaluation on the other hand comes at the end of learning, when the instructor determines to what extent their students have mastered the stated outcomes of the course. The student is judged on their knowledge or performance of skills against standards that have been set for learning. The student is also given the chance (or should be!) to formally evaluate the instructor as this feedback is essential to the betterment of the course, not to mention indicating to the instructor and even institution whether they are meeting the needs and expectations of those taking the course.