The effective performance of a computer, which is primarily one thing: speed. Computer power is generally expressed in instructions per second (IPS). The number of bytes of memory and storage, the number of bits in a word and the speed of the bus pathways (bits/bytes per second) are additional measurements of power.
However, such specifications are only guidelines. Real power includes the quality and performance of the software and whether the combination of the hardware and software gets the job done without driving the user crazy! See
instructions per second,
word and
bus.
Compute: The New Word in Town
Starting in the late 2000s as cloud computing began to flourish, the word "compute" became a synonym for computer power. As AI took over the world in the 2020s and datacenters with huge electricity appetites became mainstreamn, "compute" became "the in-word" for computer power. Techies love to coin new words for the same thing; for example, see
digital media hub terminology.
Software Is Also Powerful
An operating system or application may be called "powerful" if it has a large number of features.