army morse code pt 01

As a coded means of communication, Morse code was heavily employed for communications during World War 1 and 2. The Morse code system had a smaller communication bandwidth – it was suitable for high frequency (HF) radio waves. Skillful Morse code operators could still read a message even if the signal was distorted by noise.” More at https://www.worldhistoryedu.com/morse-code-history-and-invention/
“Morse... is still in use today. The American Navy still employs Morse code to communicate using signal lamps. Additionally, Morse code has been used to assist people with communication disabilities.”

There is a resurgence of interest in using Morse code, for a number of reasons. For example one can use Apps > https://www.techuntold.com/best-morse-code-apps/