Glossary

Why these are grouped, not alphabetised

An alphabetical list helps a reader who already knows the word. Almost nobody arriving here does: they know that something on their channel is not working and not what it is called. The shelves below are the areas a problem tends to sit in, so you can start from the symptom rather than the spelling.

The two that get mixed up most

CPM and RPM are not the same number and the gap between them is your platform cut, so a creator comparing their RPM against somebody else's quoted CPM will conclude they are failing when they are not. Watch time and retention are the other pair: one is a total that rewards long videos, the other a percentage that does not, and they move in opposite directions the moment you change format.

What a definition here does and does not do

Each entry answers one question in the first two sentences and stops. There is no history of the term, no list of synonyms, and no paragraph explaining why the concept matters before saying what it is. If a term has a number attached, that number is measured and dated on the page it came from, and the entry links there rather than repeating it.

Definitions are also the one place on this site where being incomplete is correct. An entry tells you what a word means in this trade; it does not tell you what to do about it. Where that decision is worth a page of its own, the entry points at the guide that makes it and gets out of the way.

Where the vocabulary comes from

Three sources, and they disagree more than newcomers expect. The platform names some of these things one way in its own documentation, the tools in this category name them another way in their marketing, and creators use a third set of words among themselves. Where those conflict, the entry says so and gives the platform's meaning as the one that decides your analytics, because that is the number you will actually be judged on.