Promise: then() vs await

Consider p and f (variable or expression) where

p.then(f) is the same as f(await p),
as shown in the examples below.

Ex 1: navigator.getBattery() is a Promise,
display is a function

navigator.getBattery().then(display)  is the same as
 display(await navigator.getBattery())

Ex 2: u is a URL, fetch(u) is a Promise,
call on the Response r.json() is a Promise,
ask is a function

fetch(u).then(r => r.json()).then(ask)  is the same as
 r=await fetch(u); ask(await r.json())

References

They are not exactly the same, it is strongly recommended here that await should be prefered. See also MDN docs and JS info