- Read about APIS: https://www.programmableweb.com/api-university/what-are-apis-and-how-do-they-work
- Read about Asynchronous vs. Synchronous programming: http://www.hongkiat.com/blog/synchronous-asynchronous-javascript/
- If you want to find out more about (mouse) events, check out this resource: https://www.quirksmode.org/js/events_mouse.html