FIFO
First In First Out
An ordering rule where the earliest item added is the earliest item removed or processed.
Plain English
The item that arrived first is handled first.
In context
FIFO is common in queues buffers and work intake but may be replaced by priority scheduling when urgency or fairness requires another policy.
Example
“The worker consumes messages from the queue in FIFO order.”
When you'll hear this
- queue design
- message processing
- work scheduling
Common misunderstanding
FIFO describes ordering and does not by itself guarantee exactly-once processing or completion order.
Also known as
first in first outfirst-in first-out
Commonly used by
Related terms
Updated: 2026-08-26
