Hydrus is a software application designed for managing and organizing images and other media files. It allows users to easily import, tag, and categorize their files, making it simpler to find and access them later. The program supports various file formats and offers features like batch processing and customizable metadata. Additionally, Hydrus is built around a client-server architecture, enabling users to run their own local server for enhanced privacy and control over their data. It is particularly popular among users who collect large amounts of media, such as digital artists and photographers, due to its efficient organization tools.