Clean eating is a concept where you only eat food the way nature delivered it. That means staying away from all refined and processed foods and consuming only what is the closest to food in its whole, natural form. It is not a diet program but a lifestyle approach to food and the way it is prepared.
Meal prepping is an important part of a balanced and healthy lifestyle. Other than being important to your diet, preparing your food in advance saves time and energy as well because you do not have to keep preparing your food at the same time that you want to eat something or when you get hungry.
For people who have been in a high-calorie and micronutrient-deficient diet, switching to a plant-based diet might seem very difficult because of how dependent you have been to the instant gratification and addictive feeling these unhealthy foods give.