2.1 Let's learn about the Operating System
The operating system is a software. This software is necessary to fulfil the tasks using a computer. Many tasks are such as controlling hardware and software and providing a user interface are performed by it.
🍓Provides a user interface to work easily with the computer.
🍓Controls the functions of the Central Processing Unit (CPU)
🍓Manages the computer memory efficiently.
🍓Controls the activities related to storage devices.
🍓Performs the tasks related to processing files and folders correctly.
🍓Helps to protect the computer through usernames and passwords.
🍓Manages the hardware.
2.2 Different Types of Operating Systems
Some examples for operating systems used in computers.
Some examples for operating systems used in mobile phones.
2.3 Computer Storage Devices
Data and information are in different forms such as doucments, photos, videos, animations, voices and sounds.
That data and information can be stored in computer storage devices. Similarly, computer programmes which give instructions to the computer can be stored too.
Figure 2.1 - Examples for data, information and programmes that can be stored in storage devices
Computer storage devices can be divided into several parts, according to their manufacturing technology.
1. Magnetic Media Devices. Eg: Hard Disk
2. Optical Media Devices Eg: Compact Disk
3. Solid State Media Devices Eg: Pen Drive
Functions and technology of each of the above media devices are different.
Magnetic tapes" floppy disks and hard disks are known as magnetic media devices. They consist of a magnetic surface or a magnetic tape.
• Hard Disk
The hard disk consists of a magnetised platter and a moving metal head. There are two different types of hard disks, internal hard disks and external hard disks.
A large amount of data can be stored permenently in the internal hard disk. It is a magnetic media device which is in the system unit. The external hard disk is a portable storage device. It can be chosen in various capacities such as 500 GB, 1 TB, 2 TB.
• Magnetic Tapes
A magnetic tape is a thin plastic tape covered with a magnetic substance. It is used for recording sounds, images or computer data etc. The magnatic tape which was used often in the past has now become obsolete.
• Floppy Disk
A floppy disk is a magnetic media device that can be used to store small files. It contains a capacity of 1.44 MB. It is used to carry data because it is an external storage device. But is becoming obsolete.
At present, there are disks which are produced by using the same technology used to produce the floppy disks such as zip disks and jazz disks. The capacity of these disks is greater than that of the floppy disks. But they are not used often.
In optical media devices, data is read and written by laser beams. Optical disks are of several types. They all are portable.
• CD - Compact Disks
There are two types of disks such as recordable (CD-R) and rewritable (CD-RW). The capacity of these disks are 650MB and 700MB.
2 Digital Versatile Disks (DVD)
They are of two types; DVD-R (data can be written once) and DVD - RWC (rewritable). The capacity of these disks are 4.7 GB, 8.5 GB, 15 GB and 30 GB.
2 Blue Ray Disks
In these disks, data can be stored on several levels as 25 GB on each level.
Solid state media devices are a type of device which write and read data electronically at a high speed. As they do not have moving parts as in hard disks and compact disks to write and read data, they are known as solid state media devices.
A file is anything that is saved in the computer such as a letter, a song or a photo. A file has two parts.
File name : Used to identify the file. File Extension : Used to indicate the application software of the file.
The palce where files are stored is a folder. They are used to store files that are related to each other. It helps to keep files in order and to retrieve them easily and fast.
Creating a Folder
The methods used to create a folder can be different according to the operating system. Figure 2.3 shows one such method.
Saving Files in a Folder
Files created should be saved to reuse them later. To save a file, save or Save As commands are used.
When saving a file for the first time, despite the window selected, Save As command window will open.
After selecting the folder in which the file is to be stored, by giving the sav command, the file is stored in the folder.
Opening a created Folder
The folder can be opened by taking the cursor on to the folder and double clicking on it.
Coping and Moving a Folder
A folder can be copied or moved to another location. It can be internal location or an external storage device.
First, take the cursor to the location of the folder and select it.
Changing the Name of a Folder
Step 1
To change the name of a folder, take the mouse pointer on to the folder, Then select Rename command after clicking the right button of the mouse.
Step 2
Type the required name.
Deleting a Folder
Delete temporarily
Step 1
Select the folder that needs to be deleted.
Step 2
Press the Delete button on the keyboard.
Delete Permanently
Step 1
To delete a file or a folder permanently, press Shift and Delete keys together.
Step 2
Select Yes command in the dialog box.
There are characteristics in a file or a folder such as size, type and date modified. When the mouse pointer is taken on to the relevant file or folder and when right button is clicked a menu is displayed. Select the Properties command and you can see these characteristics.
