Asynchronous and Synchronous Programming

• https://simplicable.com/new/asynchronous-processing

• https://stackify.com/when-to-use-asynchronous-programming/

• https://www.quora.com/What-is-difference-between-asynchronous-and-synchronous-in-Java

• https://stackoverflow.com/questions/748175/asynchronous-vs-synchronous-execution-what-does-it-really-mean

• https://stackoverflow.com/questions/36213948/what-is-the-difference-between-asynchronous-calls-and-callbacks

• https://stackoverflow.com/questions/14541975/difference-between-future-and-promise

• https://dzone.com/articles/when-to-use-and-not-to-use-asynchronous-programmin

• https://www.youtube.com/watch?v=lj4LmG686-I