GPU stands for graphics processing unit. The term refers to a major component of high performance computers. Its performance is much faster in many applications than a more standard CPU, central processing unit, would be.
A GPU is a programmable chip originally designed for use in gaming devices which rely intensively on graphic displays for their impact. They are often sold already installed in boards. GPUs process vectors of data efficiently making them useful in other applications, such as cryptocurrency mining. Their use has been supplanted in a number of applications, like bitcoin mining, by application-specific integrated circuits (ASICs), which are dedicated to solving a single problem. Ethereum's reliance on a memory-intensive protocol was thought to assure its resistance to ASIC-based mining but Bitmain, the largest producer of ASICs specifically for bitcoin mining, announced that it had designed miners suitable for mining ether.
The prolonged downturn experienced by cryptocurrencies during 2018 threatened the profitability of two major GPU manufacturers, AMD and Nvidia, which reported significant inventories of unsold chips.