FIFO may refer to any of the following:
1. Short for first in, first out, FIFO is a method of processing data where the data first received is the first to be sent out after processed. Below is an example of how FIFO and LIFO (last in, first out) would work. As you can see, with FIFO, the data is sent out in the same order it was received.
2. In business, FIFO (first in, first out) is one method of handling inventory. With FIFO, when the merchant buys a good, it's treated as the first sold good, even if the inventory already contains the same good. Using FIFO instead of LIFO to manage inventory helps account for inflation and other costs and gives a more accurate inventory value.