Flushes stdout. When you do print! or term-basics-linux equivalent, it will not print immediately. For example if you print! and then input_field(), it will print after you typed in the input. flush() will make sure everything is printed first.
use term_basics_linux as tbl; print("type: "); flush().expect("oh no"); let x = input_field();
This example is the same as
let x = tbl::prompt("type: ");