The document discusses three types of software:
1. Operating systems manage all other programs and allow users to interact through interfaces like GUIs. Applications use the OS through APIs.
2. Application software causes computers to perform useful tasks beyond running the computer itself. Specific applications are called software applications or apps.
3. Utility software helps analyze, configure, optimize and maintain computers, focusing on infrastructure like hardware, OSes, applications and storage. Utilities are technical and for advanced users, unlike applications.