Notational Systems – IT Fundamentals

Notational systems are the core of data representation in computing. Computers use various notational systems like binary, hexadecimal, and decimal to process and store data. They also use character encoding systems like ASCII and Unicode to represent text. Understanding these notational systems is crucial for working with computers, writing programs, and handling data in IT.

Binary Notation (Base-2)

Binary is the most basic notational system in computing. It uses only two digits: 0 and 1. These digits are called bits. Binary represents every piece of data in a computer, from numbers to text. A series of bits, like 1010, can represent any kind of information. In binary, each bit has a place value based on powers of two.

Example:
Binary: 1010 = Decimal: 10

Why It Matters:
Computers speak binary. Everything from processing instructions to storing files involves binary code.

Hexadecimal Notation (Base-16)

Hexadecimal, or hex, is a base-16 system. It uses 16 symbols: 0-9 for values 0-9 and A-F for values 10-15. Hex is often used in programming because it can represent long binary numbers in a short, readable form. Each hex digit represents four binary digits (bits).

Example:
Hex: A3 = Binary: 10100011 = Decimal: 163

Why It Matters:
Hex is great for memory addresses and color codes in web development. It’s easier for humans to read than binary.

Decimal Notation (Base-10)

Decimal is the number system we use in everyday life. It’s a base-10 system using digits 0-9. Computers don’t process decimal directly, but we often input and interpret numbers in decimal form.

Example:
Decimal: 255 = Binary: 11111111 = Hex: FF

Why It Matters:
Understanding how computers convert decimal into binary and hex helps in debugging and programming.

ASCII (American Standard Code for Information Interchange)

ASCII is a character encoding system. It uses numbers to represent characters like letters, digits, and symbols. ASCII uses 7 bits, meaning it can represent 128 characters.

Example:
ASCII: 65 = ‘A’

Why It Matters:
ASCII is the foundation of modern text encoding, especially in older systems. It’s simple but effective.

Unicode

Unicode is an expanded encoding system that represents a wide range of characters, symbols, and languages. Unlike ASCII, Unicode can use up to 32 bits. It supports over 143,000 characters from different scripts and symbols used worldwide.

Example:
Unicode: 0041 = ‘A’
Unicode: 1F600 = 😀 (Smiley Face)

Why It Matters:
Unicode powers the global digital world. It enables systems to handle multiple languages, emojis, and special symbols.

Key Information:

• Binary: Computers use this base-2 system for all data processing.
• Hexadecimal: Easier human-readable form of binary, used in programming.
• Decimal: Our everyday number system, converted by computers.
• ASCII: Encodes basic text characters using 7 bits.
• Unicode: Supports thousands of characters, enabling multiling