[gabesk]

In the simplest analogy, it's just the TV rabbit ears with two wires in opposite directions, except much longer wires, because the frequencies are lower and therefore the wavelength is larger. Those classic rabbit ears are effectively a dipole antenna, which is basically: "stretch a wire out in a line so it's half the wavelength of the frequency you want to receive or transmit on, cut it in half, and send the signal from the middle, out both ends of the cut wire".

https://www.aa5tb.com/dipole.html

Picking that length of wire results in the lowest impedance (kind of analogous to friction) at the radio for pushing signal out to the antenna, but various lengths work with more or less efficiency, and you don't have to send the signal from the middle either if you have appropriate inductors and capacitors to adjust the impedance (it's just the simplest way).

As with most things on the internet these days, it seems the best content is in the form of YouTube videos, so amusingly, this is the best written information I came across after some quick searching:

https://apps.dtic.mil/sti/tr/pdf/AD0684938.pdf