In computer architecture, 48-bit integers, memory addresses, or other data units are those that are 48 bits (6 octets) wide. Also, 48-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.
Computers with 48-bit words include the AN/FSQ-32, CDC 1604/CDC 3xxx, BESM-6, and Burroughs large systems (B5xxx-B8xxx, which additionally had a 3-4 type tag).
The IBM AS/400, in its CISC variants, is a 48-bit addressing system. The address size used in logical block addressing was increased to 48 bits with the introduction of ATA-6.
The minimal implementation of the x86-64 architecture provides 48-bit addressing encoded into 64 bits; future versions of the architecture can expand this without breaking properly written applications.
In digital images, 48 bits per pixel, or 16 bits per each color channel (red, green and blue), is used for accurate processing. Such images do not look much better than 24-bit images, but the existence of more shades between colors (65,536 as opposed to 256) means that more operations can be performed on the image without risk of noticeable banding or posterization.