A heap profiler is a tool used in software development to analyze memory usage in applications. It helps developers identify how much memory is allocated and where it is being used, which can lead to better performance and reduced memory leaks. By tracking memory allocation over time, a heap profiler provides insights into the efficiency of the code. These profilers can visualize memory usage patterns, showing which objects consume the most memory and how long they persist. This information is crucial for optimizing applications, especially in languages like Java or C++, where memory management is a key concern for performance and stability.