Virtual Memory: As we know that a computer is designed for Performing the Multiple Tasks at a Time and for this Some Memory is also used by the Computer for executing the instructions those are given by the user. But when there is a Situation when the Memory (RAM) which is required by the user is high from the Available Memory. So at that situation we will use the Concept of Virtual Memory.

Cache Memory : The Cache Memory is the Memory which is very nearest to the CPU , all the Recent Instructions are Stored into the Cache Memory. The Cache Memory is attached for storing the input which is given by the user and which is necessary for the CPU to Perform a Task. But the Capacity of the Cache Memory is too low in compare to Memory and Hard Disk

Process Control block is used for storing the collection of information about the Processes and this is also called as the Data Structure which Stores the information about the process. The information of the Process is used by the CPU at the Run time. The various information which is Stored into the PCB as followings:

1) Name of the Process.

2) State of the Process. Means Ready, Active, Wait.

3) Resources allocated to the Process

4) Memory which is provided to the Process.

5) Scheduling information.

6) Input and Output Devices used by the Process.

7) Process ID or a Identification Number which is given by the CPU when a Process Request for a Service.

Booting: When we start our Computer then there is an operation which is performed automatically by the Computer which is also called as Booting. In the Booting, System will check all the hardware’s and Software’s those are installed or Attached with the System and this will also load all the Files those are needed for running a system.

In the Booting Process all the Files those are Stored into the ROM Chip will also be Loaded for Running the System. In the Booting Process the System will read all the informationfrom the Files those are Stored into the ROM Chip and the ROM chip will read all the instructions those are Stored into these Files. After the Booting of the System this will automatically display all the information on the System. The Instructions those are necessary to Start the System will be read at the Time of Booting.

There are two Types of Booting 

1) Warm Booting: when the System Starts from the Starting or from initial State Means when we Starts our System this is called as warm Booting. In the Warm Booting the System will be Started from its beginning State means first of all, the user will press the Power Button , then this will read all the instructions from the ROM and the Operating System will b Automatically gets loaded into the System.

2) Cold Booting : The Cold Booting is that in which System Automatically Starts when we are Running the System, For Example due to Light Fluctuation the system will Automatically Restarts So that in this Chances Damaging of system are More. and the System will no be start from its initial State So May Some Files will b Damaged because they are not Properly Stored into the System.