A terabyte is a unit of measurement for digital information, equal to about one trillion bytes. To understand how big that is, think of it this way: a single terabyte can hold roughly 250,000 songs, 500 hours of movies, or 300,000 photos. If you tried to count to one trillion, counting one number per second without stopping, it would take you more than 30,000 years.

The word combines tera, a prefix meaning trillion, with byte, the basic unit computers use to store information. Computer storage has grown dramatically over time: in the 1990s, most home computers had hard drives measured in megabytes (millions of bytes). By the early 2000s, gigabytes (billions of bytes) became standard. Today, terabytes are common in laptops and phones, and data centers use petabytes (thousands of terabytes) or even exabytes (millions of terabytes).

When you download a video game that's 50 gigabytes, that's one-twentieth of a terabyte. When your family's computer has a two-terabyte hard drive, it has space for an enormous library of files, photos, and programs. As technology advances and we create more digital content, terabytes have become an everyday measure of how much information our devices can hold.