HFS+, or Hierarchical File System Plus, is a file system developed by Apple for use in its macOS operating system. It is an evolution of the original HFS and supports larger file sizes and volumes, making it suitable for modern storage needs. HFS+ also includes features like journaling, which helps protect data integrity by keeping a log of changes. This file system is commonly used on Mac computers and external drives formatted for macOS. HFS+ supports both Unicode for file names and case sensitivity, allowing for more flexible file management. However, it has been largely replaced by APFS (Apple File System) in newer versions of macOS.