The first video outlines the purpose of systems software: the operating system and utilities. It consider the role of systems software in providing a user interface and abstraction to the physical hardware. A variety of different types of user interface are explained in more detail.
The second video explains multi-tasking, memory management and device drivers.
The third video explains user and file management. The concept of handling multiple users on one computer with personal settings, and providing an abstraction of the physical file system into logical folders for the user.
The fourth video explores a small range of typical utility software that could be examined at GCSE. This includes encryption, defragmentation, data compression and backup: both full and incremental.