Byte facts for kids

A byte is a unit of measurement for the size of information on a computer or other electronic device. Think of it like measuring length in meters or weight in kilograms.

A single byte is usually made of eight smaller pieces called bits. Bits are the smallest unit of storage on a computer, like a tiny on/off switch. Bytes are often shown with a big B (like MB for megabytes), while bits use a small b (like Mbit for megabits).

One byte can store one typed character, such as 'x' or '8'. The computer stores this character as a binary number. To know which number means which character, computers use special codes like ASCII. EBCDIC is another code, mainly used on large mainframe computers. It uses 8 bits per byte. ASCII usually uses seven bits, but Extended ASCII uses 8 bits for more characters, especially on personal computers.

The byte is the smallest useful way to measure how much information a computer or electronic device can hold. This is helpful for things like RAM (your computer's short-term memory) or storage devices like USB drives. When data is sent over a modem or Wi-Fi, it's usually measured in bits, not bytes.

Today, one byte is always eight bits. Some older computers used fewer bits for a byte. To avoid confusion, computer experts sometimes called an 8-bit byte an octet. But now, "octet" and "byte" mean the same thing.

What Do 'B' and 'b' Mean?

The symbol for "byte" is "B". Sometimes you might see a small "b" used, but this is usually wrong. The small "b" is the symbol for "bit". This difference is important!

For example, "MB" means "megabyte," and "Mbit" means "megabit."

• 1 megabyte (MB) is 1,000,000 bytes.
• 1 megabit (Mbit) is 1,000,000 bits, which is only 125,000 bytes (because 1,000,000 / 8 = 125,000).

Bits are much smaller than bytes. So, remember to use "b" for bits and "B" for bytes!

Bigger Units of Bytes

When we talk about very large amounts of data, we use prefixes with "byte." Here are some common ones:

• Kilobyte (KB)
• Megabyte (MB)
• Gigabyte (GB)
• Terabyte (TB)

There are even larger units, but they are not used very often:

• Petabyte (PB)
• Exabyte (EB)
• Zettabyte (ZB)
• Yottabyte (YB)

How We Count Bytes

There can be some confusion about how we count bytes, especially with terms like "kilobyte." This is because there are two main ways to count: using powers of 10 (like in the metric system) or using powers of 2 (which computers often use).

The International Electrotechnical Commission (IEC) sets many computer standards. They suggest specific ways to refer to these units.

People who say 1 kilobyte is 1,024 bytes are technically using an older way of thinking. According to the IEC, 1,024 bytes should be called 1 kibibyte. However, using 1,024 for "kilo" was common before the IEC standards were set in 1998. This is why you might still see different uses today. For example, Computer memory is often still measured in powers of 2 (so 1KB of memory is 1024 bytes), while computer data storage often uses powers of 10 (so 1KB is 1000 bytes).

"Kilo-" = 1,000

When we use standard metric names like "kilo-," "mega-," and "giga-," they should follow the same rules as other metric measurements. For example, a kilometer is 1,000 meters, and a gigahertz is 1,000,000,000 hertz.

"Kibi-" = 1,024

Computers use the binary numeral system (base 2) instead of the common decimal numeral system (base 10). This means that memory sizes often work best with powers of 2. For example, 2¹⁰ is 1,024.

To make things clearer, the IEC created new names for units based on powers of 2. These names have "bi" in them, like "kibibyte."

See also

In Spanish: Byte para niños