Data in system memory can be easily lost due to volatile storage technology. When power is off, or the system crashes, all data in memory is lost. As a result, we require hardware and software to store data persistently.

Hard drives and SSDs$,$ which are input$/$output $($I$/$O$)$ devices, are popular for storing long$-$term data. The operating system handles these as part of the file system, which is responsible for storing user files reliably and efficiently.

Unlike the OS$$s CPU and memory abstractions$,$ the operating system does not create a private, virtualized drive for each program. Instead, users are expected to share file$-$based information regularly.