​Computer Technology - Data Representation and Number Systems
​Computers store and process all data in binary form (0s and 1s). However, binary is not always easy for humans to read or use. To make data more understandable and practical, we use different number systems (notations) to represent and interpret this binary data.
These notational systems allow us to represent numbers, text, and other types of data in ways that are easier for humans and software to work with.

1. Binary (Base 2)
Explanation:
Binary is the fundamental language of computers. It uses only two digits:

• 0 (off)
• 1 (on)

All data—numbers, text, images, and videos—are ultimately stored as binary.
Example:
The number 5 in binary is 101

2. Decimal (Base 10)
Explanation:
Decimal is the number system humans use every day. It uses ten digits:

• 0 to 9

Example:
The number 245 in decimal is what we commonly use in daily life.

3. Hexadecimal (Base 16)
Explanation:
Hexadecimal (or “hex”) uses sixteen symbols:

• 0–9 and A–F (where A=10, B=11, … F=15)

It is often used in computing because it is a shorter, more readable way to represent binary data.
Example:
Binary 1111 = Hexadecimal F

4. Octal (Base 8)
Explanation:
Octal uses eight digits:

• 0–7

It was more commonly used in older computing systems but still appears in some areas like file permissions in operating systems.
Example:
Binary 111 = Octal 7

Summary
​Although computers use binary internally, humans rely on different number systems to make data easier to understand:

• Binary (Base 2): Used by computers
• Decimal (Base 10): Used by humans
• Hexadecimal (Base 16): Compact form of binary
• Octal (Base 8): Simplified binary representation (less common today)

These systems help bridge the gap between how computers store data and how humans interact with it.