4TB

4 TB, or four terabytes, is a unit of digital information storage. In decimal terms, 1 TB equals 1,000,000,000,000 bytes, so 4 TB equals 4,000,000,000,000 bytes. In binary terms, this capacity is about 3.64 tebibytes (approximately 3,725 gibibytes).

Commonly used to describe the capacity of consumer storage devices such as hard disk drives (HDDs), solid-state drives (SSDs), external USB drives, and network-attached storage (NAS). A 4 TB drive is suitable for large backups, media libraries, and software collections. Rough usage examples: it can store thousands of high-resolution photos, tens of hours of 4K video, or a substantial software library, depending on file formats and compression.

Manufacturers usually market drives in decimal terabytes, while operating systems often report capacity in binary units, causing the displayed size to appear smaller than the labeled figure. Additionally, actual usable space is reduced by formatting, the file system, and, for SSDs, wear-leveling and over-provisioning. As a result, usable capacity on a 4 TB drive may be roughly 3.6 to 3.9 TiB depending on the device and file system.