A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Modern computers have the ability to follow generalized sets of operations, called programs. These programs enable computers to perform an extremely wide range of tasks.
From then on, when anything went wrong with a computer, we said it had bugs in it.
RADM Grace Hopper, on the removal of a 2-inch-long moth from the Harvard Mark I experimental computer at Harvard in August 1945, as quoted in Time (16 April 1984)