Hematoxylin and Eosin (H&E) is a widely used staining technique in histology, the study of tissues. Hematoxylin stains cell nuclei blue, highlighting their structure, while eosin stains the cytoplasm and extracellular matrix pink. This contrast allows pathologists to examine tissue samples under a microscope effectively. H&E staining is essential for diagnosing diseases, including cancer, by providing clear visual differentiation of cellular components. It helps in identifying abnormalities in tissue architecture and cellular morphology, making it a fundamental tool in medical research and clinical practice.