ARTICLE CONTENTSOn this page 10 sections
Basic Computer Hardware Components II: Storage Units
Performance Objectives
By the end of the lesson, students should be able to:
- state the meaning of storage;
- state the meaning of unit bit, byte, kilobyte, etc.;
- describe storage capacity based on storage units;
- convert from one unit to another.
Meaning of Storage
Storage is the process of saving and keeping data or information in a computer device for future use.
Computers process large amounts of data. To prevent this data from being lost when the computer is switched off, it must be saved on a storage medium. Storage allows computer programs, documents, pictures, music, and videos to be kept safely so that they can be opened and used again at any time.
Meaning of Computer Storage Units
A storage unit is a standard measurement used to express the amount of data a computer device can hold.
Just as liquids are measured in litres and physical weights are measured in kilograms, digital data is measured using specific computer storage units. These units help computer users understand the size of files and the capacity of storage devices.
The Bit
A bit is the smallest unit of data that a computer can process or store.
The word “bit” is short for “binary digit”. A bit can only have one of two values, which are represented by the numbers 0 and 1. Computers use electrical circuits that can either be off (representing 0) or on (representing 1). Every piece of information inside a computer is broken down into these basic 0s and 1s.
The Byte
A byte is a unit of digital information that consists of eight bits grouped together.
A single byte is the amount of storage space required to store one character, such as a single letter, a number, or a punctuation mark. For example, the letter “B” takes up exactly one byte of storage space in a computer.
Observe the diagram below to see how bits group together to form a byte.
The Hierarchy of Storage Units
As files become larger, measuring them in bytes becomes difficult because the numbers become too large. Therefore, larger storage units are used to measure data. These units include the kilobyte, megabyte, gigabyte, and terabyte.
Kilobyte (KB)
A kilobyte is a unit of data storage that is equal to 1,024 bytes.
A short text document or a single page of plain text usually has a file size of a few kilobytes.
Megabyte (MB)
A megabyte is a unit of data storage that is equal to 1,024 kilobytes.
This unit is commonly used to measure the size of digital photos, music files, and small software applications. For example, a typical three-minute song is about 3 to 5 megabytes in size.
Gigabyte (GB)
A gigabyte is a unit of data storage that is equal to 1,024 megabytes.
This unit is used to measure larger files and the storage capacity of common devices like mobile phones and USB flash drives. A high-definition movie is usually between 1.5 and 4 gigabytes in size.
Terabyte (TB)
A terabyte is a unit of data storage that is equal to 1,024 gigabytes.
This is a very large unit of storage. It is used to measure the capacity of modern computer hard drives and large external storage devices. A one-terabyte drive can hold hundreds of thousands of digital photos or hundreds of movies.
The main storage units used in computing are:
- Bit (b)
- Byte (B)
- Kilobyte (KB)
- Megabyte (MB)
- Gigabyte (GB)
- Terabyte (TB)
Look at the staircase diagram below to understand the hierarchy of these units from the smallest to the largest.
Describing Storage Capacity
Storage capacity is the maximum amount of data that a storage device can contain.
Different storage devices are designed with different storage capacities to suit different purposes. Understanding these capacities helps computer users choose the right device for their files.
Examples of common storage devices and their typical capacities include:
- Compact Disc (CD): Typically holds about 700 megabytes (MB) of data.
- Digital Versatile Disc (DVD): Typically holds about 4.7 gigabytes (GB) of data.
- USB Flash Drive: Commonly ranges from 8 gigabytes (GB) to 128 gigabytes (GB) of data.
- Memory Card: Commonly ranges from 16 gigabytes (GB) to 256 gigabytes (GB) of data.
- Computer Hard Drive: Commonly ranges from 500 gigabytes (GB) to 2 terabytes (TB) of data.
The table below provides a summary of storage units, their abbreviations, their exact values, and real-world examples of what they can hold.
| Storage Unit | Abbreviation | Equivalent Value | Real-World Example |
|---|---|---|---|
| Bit | b | 0 or 1 | A single on/off electrical state. |
| Byte | B | 8 bits | A single letter or character (e.g., “A”). |
| Kilobyte | KB | 1,024 Bytes | A short email or half a page of typed text. |
| Megabyte | MB | 1,024 Kilobytes | A high-quality digital photograph or a music track. |
| Gigabyte | GB | 1,024 Megabytes | A high-definition movie or a mobile game. |
| Terabyte | TB | 1,024 Gigabytes | A computer hard drive containing thousands of books and videos. |
Conversion of Storage Units
Converting storage units means changing a measurement of data from one unit to another. This is done using basic mathematical calculations based on the relationships between the units.
The conversion rules are based on the following relationships:
- 8 Bits = 1 Byte
- 1,024 Bytes = 1 Kilobyte (KB)
- 1,024 Kilobytes = 1 Megabyte (MB)
- 1,024 Megabytes = 1 Gigabyte (GB)
- 1,024 Gigabytes = 1 Terabyte (TB)
Rules for Conversion
To convert from a larger unit to a smaller unit (for example, from Gigabytes to Megabytes), multiply by the conversion factor (1,024).
To convert from a smaller unit to a larger unit (for example, from Kilobytes to Megabytes), divide by the conversion factor (1,024).
To convert between bits and bytes, use the number 8 instead of 1,024.
Worked Examples
Example 1: Convert 5 Megabytes (MB) to Kilobytes (KB).
Since Megabytes are larger than Kilobytes, multiply by 1,024.
Calculation:
5 × 1,024 = 5,120 KB
Answer: 5,120 KB
Example 2: Convert 3 Gigabytes (GB) to Megabytes (MB).
Since Gigabytes are larger than Megabytes, multiply by 1,024.
Calculation:
3 × 1,024 = 3,072 MB
Answer: 3,072 MB
Example 3: Convert 2,048 Kilobytes (KB) to Megabytes (MB).
Since Kilobytes are smaller than Megabytes, divide by 1,024.
Calculation:
2,048 ÷ 1,024 = 2 MB
Answer: 2 MB
Example 4: Convert 32 Bits to Bytes.
Since bits are smaller than bytes, divide by 8.
Calculation:
32 ÷ 8 = 4 Bytes
Answer: 4 Bytes
Example 5: Convert 2 Terabytes (TB) to Kilobytes (KB).
This conversion requires multiple steps down the hierarchy.
Step 1: Convert Terabytes to Gigabytes.
2 × 1,024 = 2,048 GB
Step 2: Convert Gigabytes to Megabytes.
2,048 × 1,024 = 2,097,152 MB
Step 3: Convert Megabytes to Kilobytes.
2,097,152 × 1,024 = 2,147,483,648 KB
Answer: 2,147,483,648 KB
How to Check Storage Capacity on Digital Devices
Checking the storage capacity of a digital device helps a user know how much space is available for files and applications.
The procedure for checking storage capacity on a Windows computer involves the following steps:
- Turn on the computer and wait for the desktop screen to load.
- Double-click on the “This PC” or “File Explorer” icon on the desktop.
- Look at the section labelled “Devices and drives”.
- Observe the hard disk drive icon (usually labelled Local Disk C:).
- Read the numbers showing the free space and the total storage capacity of the drive.
The procedure for checking storage capacity on an Android mobile device involves the following steps:
- Turn on the mobile device and open the main menu.
- Locate and tap on the “Settings” application icon.
- Scroll down the settings menu and tap on “Storage” or “Device Care”.
- Observe the screen to see the total storage capacity of the device.
- Read the breakdown showing how much storage is used by applications, images, videos, and system files.
Summary
Computer storage units are essential for measuring the size of files and the capacity of storage devices. From the tiny bit to the massive terabyte, each unit plays a specific role in digital technology. Knowing how to convert these units allows computer users to manage their files and storage devices effectively.
Evaluation Questions
The evaluation questions are:
- What is the meaning of computer storage?
- Define the terms “bit” and “byte”.
- List the six main computer storage units in order from the smallest to the largest.
- Describe the storage capacity of a standard Compact Disc (CD) compared to a standard Digital Versatile Disc (DVD).
- Convert 4 Megabytes (MB) to Kilobytes (KB).
- Convert 4,096 Megabytes (MB) to Gigabytes (GB).
- Convert 1 Terabyte (TB) to Megabytes (MB).
0 comments
Open the discussion when you need it. Comments stay collapsed until requested so the initial article remains light.