Deep learning is a type of machine learning that uses multiple processing layers to learn representations of data with features that become more complex at each layer. Deep learning has achieved human-level performance in areas like image recognition by learning from large datasets. In healthcare, deep learning has been applied to tasks like detecting pneumonia from chest X-rays and skin cancer from images with accuracy comparable to doctors. However, challenges remain around data variability, uncertainty, class imbalance, and data annotation. Cross-area collaboration and data sharing are seen as key to realizing the potential of deep learning in healthcare.