Bottom-up processing is a cognitive approach where perception starts with the sensory input. In this process, the brain takes in raw data from the environment, such as light, sound, or touch, and builds a perception based on that information. For example, when you see a flower, your eyes detect colors and shapes, which your brain then organizes to recognize it as a flower. This method contrasts with top-down processing, where prior knowledge and expectations influence perception. Bottom-up processing is essential for understanding new stimuli, as it relies solely on the information provided by the senses without preconceived notions.