WhatTheDiff is a software tool designed to automate and enhance the process of reviewing code changes, known as "diffs." By leveraging artificial intelligence, WhatTheDiff generates high-quality summaries of code changes, allowing developers to quickly understand the essence of a code modification without manually sifting through detailed lines of code. This tool is particularly useful for code review processes, making it easier to assess the purpose and impact of changes, thus streamlining collaboration and reducing review times.