Primary growth is like when a baby grows taller and bigger. When a plant is a baby, it also grows bigger and taller through primary growth. Just like how we have bones that grow, plants have something called meristems that help them grow taller and bigger. These meristems are like the plant's bones that help with its primary growth. As the plant grows bigger, it also gets more leaves, stems, and roots. This is important because it allows the plant to get more nutrients and sunlight from the environment. Growing bigger and taller through primary growth is essential for a plant to survive and thrive.