What is a bit?
The word bit is short for binary digit.
- A bit can only be
0or1. - With bits, computers represent all types of information: text, images, music.
What is a byte?
A byte is made up of 8 bits. Example:
01001011
With 8 bits, we can represent 2⁸ = 256 different combinations.
2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 256
Practical Examples
| Unit | Composition | Possibilities | Use |
|---|---|---|---|
| 1 bit | 0 or 1 | 2 | on/off |
| 2 bits | e.g. 01, 10 | 4 | 4 symbols |
| 4 bits | e.g. 1100 | 16 | numbers from 0 to 15 |
| 8 bits = 1 byte | e.g. 10110101 | 256 | one character |
What is a byte used for?
The byte is the unit of memory used in digital devices.
- The word HELLO = 5 bytes = 40 bits
- An image of 100 KB = about 100,000 bytes
Powers of Two
The number of possible combinations using a certain number of binary digits is closely related to the powers of 2.
| 2ⁿ | Value | Use |
|---|---|---|
| 2⁰ | 1 | minimum value |
| 2¹ | 2 | two states (bit) |
| 2³ | 8 | 1 byte |
| 2⁴ | 16 | base colors |
| 2⁸ | 256 | 1 character |
| 2¹⁰ | 1024 | 1 kilobyte |
| 2²⁰ | 1,048,576 | 1 megabyte |
| 2³⁰ | 1,073,741,824 | 1 gigabyte |
Memory and Storage
The memory storage of electronic devices is defined in multiples of the byte.
| Name | Symbol | Equivalent |
|---|---|---|
| Kilobyte | KB | ≈ 1,024 bytes |
| Megabyte | MB | ≈ 1,024 KB |
| Gigabyte | GB | ≈ 1,024 MB |
| Terabyte | TB | ≈ 1,024 GB |
