What is the definition of XT computer?

The first IBM computer with a built-in hard drive

When referring to a computer, XT is short for extended technology and is the name of the IBM 5160 computer introduced on March 8, 1983. The XT was the first IBM computer with a hard drive (10 MB or 20 MB) ... XT is also a bus introduced in 1982 that had four DMA channels, was 8-bit, and had a bus speed of 4.77 MHz