A heat map is a data visualization tool that uses color to represent the intensity or frequency of data points in a specific area. It helps to quickly identify patterns, trends, and anomalies within large datasets. Commonly used in fields like marketing, healthcare, and urban planning, heat maps can display information such as website traffic, disease outbreaks, or population density. Typically, heat maps use a gradient of colors, where warmer colors (like red or orange) indicate higher values, while cooler colors (like blue or green) represent lower values. This visual representation makes it easier for users to interpret complex data at a glance, facilitating better decision-making and analysis.