Computer Skills Course: Bits, Bytes, Kilobytes, Megabytes, Gigabytes, Terabytes (UPDATED VERSION)

Digital Storage Units

Computers store information using binary digits—ones and zeros—and combine these bits into larger units.

• Bit: Short for “binary digit.” A bit is the smallest unit of data and is represented as a 1 or 0. Bits can represent all kinds of information, including text, photos, and sound.
• Byte: A group of 8 bits. One byte can represent about one text character, so a 500-character paragraph takes roughly 500 bytes.
• Kilobyte (KB): About 1,000 bytes. In binary-based measurements, a kilobyte is 1,024 bytes, but for everyday use, it is fine to think of it as 1,000. A kilobyte can hold about a third of a page of text.
• Megabyte (MB): About 1,000 kilobytes. As rough examples, one megabyte could hold about one book, one photo, or one minute of music. The amount varies with quality and encoding. A 3.5-inch floppy disk could hold 1.4 MB.
• Gigabyte (GB): About 1,000 megabytes. The video estimates that this could hold about 1,000 books, 1,000 photos, or 16 hours of music. It contrasts the expense of 1 GB hard drives in the mid-1990s with the low cost—and limited usefulness—of 1 GB removable storage today.
• Terabyte (TB): About 1,000 gigabytes. The video estimates that this could hold about a million books (roughly 80 school libraries), a million photos, or two years of continuous music. Terabyte-scale storage is readily available in several forms.

Size Progression

For everyday use:

8 bits = 1 byte → 1,000 bytes = 1 kilobyte → 1,000 kilobytes = 1 megabyte → 1,000 megabytes = 1 gigabyte → 1,000 gigabytes = 1 terabyte

The larger units that follow are petabyte, exabyte, zettabyte, and yottabyte.

Speakers and Source

• Speaker: One narrator/instructor; no other speakers are featured.
• Source/channel: Dane Hartman