BBBIT Similarities?How have they similar?

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By the end of today’s lesson;• All of you will understand the purpose of

a virtual machine (D-E)• Most of you will know why some

operating systems use a virtual machine(B-C)

• Some of you will be able to describe the differences between a system VM and a process VM (A*-A)

Learning Outcomes

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The Virtual Machine is presented by the Operating System to the user, hiding all the complexities of the hardware behind layers of OS software. The final layers of the operating system are the user Interface and the Application programming interface, which calls on the services of the Operating System.

What is a VM?

BBBIT• Hardware• Kernel - the bridge between the

Hardware components and the Applications

• Device drivers• Processor management• Memory management• File management• I/O management• User Interface/API

What layers it covers

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Application Programming Interface

Not all machines should be expected to have exactly the same setup. The Application Programming Interface (API) makes it possible for the same piece of program to be used on different computers. It is the layer of the software that allows the application programs to call on the services of the OS

API

BBBITBeing the most fundamental of all system programs, Operating Systems are trust with the job of controlling and sorting through the hardware, and this includes all the main components of the computer. To ensure that there is little confusion, the OS programs managing the key resources are giving relatively simple names depending on the resource they manage:

Resource Management

Key Resource OS ProgramProcessors Processor SchedulingStorage Memory managementI/O devices I/O managementData File management

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1. Finish off last lessons OS work2. Describe what a VM is3. Explain the different layers of an

OS4. Explain API5. Describe how an operating system

manages the computers resources.

Your Task