On lichess.org, when you turn the opening book on in an analysis board, you get names for the openings. For example, after 1.e4 d6 2.d4 Nf6 3.Nc3 c6, lichess says the opening is called "Czech Defense." Many openings have standard, accepted names, but sometimes there is disagreement, especially with deep variations. There is also sometimes disagreement between different playing platforms. For example, sometimes chess.com uses different names than lichess. What sources provide lichess all of the names?
Lichess is open source. That source includes a table of openings compiled by the contributors to lichess.
And if you want to see who exactly made what change/addition to the list, you can click on the
.tsv file in question and examine the history.