Eric Lippert explains the reasons why `async` was chosen for C# here: https://docs.microsoft.com/en-au/archive/blogs/ericlippert/asynchrony-in-c-5-part-six-whit

Eric Lippert explains the reasons why `async` was chosen for C# here: https://docs.microsoft.com/en-au/archive/blogs/ericlippert/asynchrony-in-c-5-part-six-whither-async https://docs.microsoft.com/en-au/archive/blogs/ericlippert/a.... Other languages have used the same keyword either for their own good reasons or just because they wanted to copy what was being used elsewhere. Note that even without `async`, you’d still have red and blue functions (those which contain `await` and those which don’t), it would just be harder to tell which was which.