https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest_API/Synchronous_and_Asynchronous_Requests
Synchronous and asynchronous requests - Web APIs | MDN
XMLHttpRequest supports both synchronous and asynchronous communications. In general, however, asynchronous requests should be preferred to synchronous...
synchronous and asynchronousweb apisrequestsmdn
https://nullprogram.com/blog/2017/02/14/
Asynchronous Requests from Emacs Dynamic Modules
asynchronous requestsdynamic modulesemacs
https://www.codecademy.com/learn/becj-22-async-javascript-and-http-requests/modules/wdcp-22-basics-of-asynchronous-javascript-8dab3ddb-6fd6-46ac-8813-49815ac24ac1/cheatsheet
Async JavaScript and HTTP Requests: Basics of Asynchronous JavaScript Cheatsheet | Codecademy
http requestsasyncjavascriptbasicscheatsheet