Comment by thombles

For today's 10000: amateur radio operators call Morse code "CW" since it's a Continuous Wave (unmodulated) transmission while you're pressing the key. The most basic kind is a straight key which simply transmits when you push and stops when you let go. Electronic keyers often use iambic paddles/buttons where you use one switch to create a series of "dits" and the other switch to create "dahs" yourself, which is less physically demanding and lets you hit higher WPM. There are examples of both types here.