Glossary term
What is Latency? Meaning for developers
In System Design
Time to complete one request. Example: "The API responds in 80 ms.".
Learn it properly · System DesignLesson 8: Latency, Throughput & Why p99 MattersAn 80 ms average can hide a checkout that freezes for five seconds. Latency, throughput and Little's Law, why queues explode near full utilisation, and why at scale the p99 becomes what most users feel.In Networking for Developers
How long one trip takes; RTT is the time for a message to go out and the reply to come back.
Learn it properly · Networking for DevelopersLesson 0: How the Internet Works: Layers, Packets and AddressesThe layer models, what a packet is, MAC, IP and ports, and following one request from your laptop to a server.