Glossary
Every term the courses use, defined in one line and then in a paragraph. Written to be read out of order.
Showing 4 of 124
Time spent waiting rather than working.
The delay before a response begins. Largely set by physical distance and the number of round trips, not by processing speed. London to Virginia is about 80ms round trip no matter how good your code is.
See also Round trip, Edge, CDN
What is shown while a request is in flight.
One of four states every piece of loaded data has. Best delayed slightly so fast responses do not flicker, then held briefly once shown so it does not flash.
See also Empty state, Skeleton
This machine, talking to itself.
The address a computer uses for itself. Reachable only from that machine, which is why your dev server is not visible to anyone else on the internet.
A record of individual events.
Detailed entries about specific things that happened. Excellent for investigating one failure, poor for spotting trends, and expensive at volume. Log identifiers, never raw request bodies.
See also Metrics, Tracing, Observability