No views means someone clicked. Reads means they stayed to read for 30 seconds or more. If they click but don't read, it adversely affects your read ratio and that can mean your earnings are lower.

Yes, read values vary depending on how often someone reads your work, how much they read on the platform as a whole, and whether they are a friend of Medium, as well as factors like whether they follow you, and to what extent they engage when they read.