Single-cell analysis is a technique used to study individual cells, allowing researchers to understand the unique characteristics and behaviors of each cell type. This method is crucial for uncovering cellular diversity within tissues, which can reveal insights into development, disease, and responses to treatments. By examining cells one at a time, scientists can identify differences in gene expression, protein levels, and metabolic activity. This approach is particularly valuable in fields like cancer research, where understanding the heterogeneity of tumor cells can lead to more effective therapies.