The Storage Unit Hierarchy

The Storage Unit Hierarchy

From Smallest to Largest:

1. Bit (b) - The Smallest Unit:

• A single binary digit: 0 or 1
• Can represent: on/off, true/false, yes/no
• Symbol: lowercase 'b' (e.g., 100 Mb/s = megabits per second)
• Used for: network speeds, download speeds

2. Byte (B) - 8 Bits:

• 1 byte = 8 bits
• Can represent: one character (letter, number, symbol)
• Symbol: uppercase 'B' (e.g., 100 MB/s = megabytes per second)
• Range: 0 to 255 (2⁸ = 256 different values)
• Example: The word "Hi!" = 3 bytes (3 characters)

3. Kilobyte (KB) - ~1,000 Bytes:

• 1 KB = 1,024 bytes (binary) or 1,000 bytes (decimal)
• Can store: a paragraph of text, a small icon
• Example: Short email (5-10 KB), small webpage (50 KB)

4. Megabyte (MB) - ~1,000 KB:

• 1 MB = 1,024 KB = 1,048,576 bytes
• Can store: a photo, a minute of MP3 music, a short video
• Example: High-res photo (3-5 MB), 1 minute MP3 (1 MB)

5. Gigabyte (GB) - ~1,000 MB:

• 1 GB = 1,024 MB = 1,073,741,824 bytes
• Can store: a feature film, 300 photos, 250 songs
• Example: HD movie (4-8 GB), PC game (20-50 GB), smartphone storage (64-256 GB)

6. Terabyte (TB) - ~1,000 GB:

• 1 TB = 1,024 GB = 1,099,511,627,776 bytes
• Can store: 250 HD movies, 250,000 songs, 500,000 photos
• Example: Hard drives (1-20 TB), Netflix server storage

7. Petabyte (PB) - ~1,000 TB:

• 1 PB = 1,024 TB = 1,048,576 GB
• Can store: 500 billion pages of text, 13 years of HD video
• Example: Google processes ~20 PB of data per day, Facebook stores ~300 PB of photos

8. Exabyte (EB) and Beyond:

• 1 EB = 1,024 PB - entire internet traffic in 2000 was ~2 EB
• 1 ZB (Zettabyte) = 1,024 EB - global data created per year (~64 ZB in 2020)
• 1 YB (Yottabyte) = 1,024 ZB - theoretical, not yet used in practice