Answer:
MULTITASKING OS
Step-by-step explanation:
MULTITASKING OPERATING SYSTEM is an operating system that enables and allow user of either a smartphone or computer to make use of more that one applications program at a time.
Example with MULTITASKING OPERATING SYSTEM smartphones user can easily browse the internet with two applications program like chrome and Firefox at a time or simultaneously
Therefore a user working with two apps simultaneously is an example of a unit that uses a MULTITASKING OS.