1. Human–computer interfaces

2. Operating systems are software (i.e. programs)
used to control the hardware directly
used to run the applications software

3. Functions of operating systems 1
Manage and control devices.
Provide a user interface.
Hide the complexity of hardware from user.
Deal with errors.
Provide interface between applications software and hardware.

4. Functions of operating systems 2
Allow installation of new hardware and software.
Utilities for virus scanning, encryption, etc.
Handle the storage of data.
Maximize memory use.
Automatically recognize new hardware.
Organize resources when tasks are being worked on simultaneously.

5. Types of user interface
graphical user interface (GUI)
command line
voice driven
menu/dialogue boxes
touch sensitive
biometric