Over at LockerGnome.net, a user asked, “What does 1 TB mean?”

This question actually has multiple answers, depending on what it is you’re inquiring about. Virtual storage, processors, and hard drives have different definitions for exactly what makes a terabyte. To explain why there is a difference, let’s first look at a how these measurements of virtual data actually work.

Bit
A bit is the smallest measurement of data a computer recognizes. In a sense, if all data was broken down to 1s and 0s, the bit would be a single digit in the long series of numbers. The numbers represent on and off, which is a throwback to the early days of computing when data was translated using hardware circuits that were either flipped on or off. Because this method for relaying information to a computer worked, the concept stuck and continues to this day. This basic computer language is referred to as binary, and it’s easier to understand than it seems.

Byte
A byte is made up of 8 bits. Instead of representing a single on or off state, a byte is capable of 256 different combinations. This means it can represent a single number, letter, and in some cases even color. The C and C++ programming standard defines a byte as an, “addressable unit of data large enough to hold any member of the basic character set of the execution environment.”

Kilobyte
Here is where the similarities end. The kilobyte represents 1,000 bytes in the world of hard drives and 1,024 in the world of virtual data. This means for every kilobyte of virtual data you need stored, your hard drive will come up 24 bytes short in comparison. An average image embedded on a Web page is about 40-65 kilobytes in size.

Megabyte
This is the most commonly referred-to measurement of data. It represents 1,000 or 1,024 kilobytes, and roughly enough data to store a minute-long mp3. A long time ago, in our own galaxy, the most common form of portable data storage was called a floppy disk which held only 1.44 megabytes of data.

Gigabyte
A gigabyte represents 1,000 or 1,024 megabytes. A single gigabyte of storage can hold about 240 4-minute songs at 128 kbps. The first iPod had a 5 GB drive and was sold with the pitch line, “1,000 songs in your pocket.”

Due to the differences in measurements between digital data and advertised hard drive capacity, a 500 GB hard drive has an actual virtual storage capacity of about 451 GB.

Terabyte
A terabyte is 1,000 or 1,024 gigabytes. Currently, you’re most likely to see this measurement in relation to a hard drive storage capacity. Unlike the gigabyte, terabyte and larger drives are presently broken down in to halves and wholes, while drives measured in gigabytes come in a wider variety of capacities from 1 to 750. A 1.5 terabyte hard drive contains about 1,500 gigabytes which breaks down to 1,500,000,000,000 bytes. In 2011, the first 4.0 terabyte hard drive was unveiled by Samsung.

A terabyte is capable of storing roughly 250,000 4-minute mp3s and about 500 standard 4.4 GB dvds.

To put it simply, 1 TB is a lot of space. While it is certainly possible to fill this up given the massive amounts of HD video available for download, it isn’t very likely an average user will fill one of these up very quickly.