# 3.3.3 Units of Information

## 1 Base Number and Units

### Learn It

Binary Bits

• Computers are made up of electronic hardware that can store and process data.
• A computer can be broken down into basic components which contain millions of IC circuits that either do or do not allow electicity to flow through them.
• IC circuits are like rows of switches that can either be on or off, different combinations can mean different things.
• Each switch can be represented by 1 or 0. This is called binary.
• A single 1 or 0 is a Binary digIT, or a BIT for short.
• A byte is a group of eight bits.
• A nibble is a group of 4 bits or half a byte.

### Learn It

#### Units

• A byte is the smallest addressable unit of memory in a computer. Just like a kilometer is a 1000 meters, we can group together a 1000 bytes to make a kilobyte.
• Memory size is measured in the following multiples:
Unit Number of bytes Decimal value Equivalent to
Kilobyte(KB) 103 1,000 1024 bytes
Megabyte(MB) 106 1,000,000 1024 kilobytes
Gigabyte(GB) 109 1,000,000,000 1024 megabytes
Terabyte(TB) 1012 1,000,000,000,000 1024 gigabytes
Petabyte(PB 1015 1,000,000,000,000,000 1024 terabytes
Exabyte(XB) 1018 1,000,000,000,000,000,000 1024 petabytes
Zettabyte(ZB) 1021 1,000,000,000,000,000,000,000 1024 exabytes
Yotabyte(YB) 1024 1,000,000,000,000,000,000,000,000 1024 zettabytes

• 1MB = 1000KB etc. Internal memory often use the Kibibyte, where 1KiB (Kibibyte) = 210 = 1,024 bytes, MiB (Mebibyte) = 220 = 1,048,576 bytes, and so on.

• Silver: Answer the following 3 questions and submit to www.bournetolearn.com
```1. How many bytes in a 1,000 Exabyte?
2. Convert 5600MB into GB.
3. Convert 1000TB into GB.
```

```1. What is meant by a bit?