A good balance is to eat more vegetables than any other food group. An imbalanced diet would be one that includes more pasta than vegetables.
Balance is a major concern when people consider a plant-based diet plan, because we have been taught that animal products are an important food group.
But if you look at that food group as protein rather than meat, there are lots of excellent vegetarian and vegan foods that can balance your diet.
Balance also involves your own personal balance. Some people do better with a lot of raw foods, while others do better with more cooked foods. Even if you learn about something that is nutritionally good in theory, it may not be right for you. Be careful of diet plans that stick rigidly to an idea of what perfect nutrition should be.