Dif between 16:9 and squeeze?

I am not sure if this has been asked before, but I am not clear what are the differences between 16:9 and squeeze. Also I am thinking of buying a anamorphic lens. Is that a good investment? I have read that it only works at certain zoom levels, is that true?

Thanks in advance.

Squeeze and anamorphic 16:9 are the same thing. It's called squeeze because when viewed at 4:3, the video looks like it was squeezed horizontally like an accordion. This was done because when 16:9 came along, all the TV broadcast formats were 4:3 and so the 16:9 had to be compatible with the 4:3 electronics. In order to do that, they retained all the 4:3 parameters except the pixel shape in 16:9 is wider than 4:3. The DVD player or the electronics in the TV sort that out for you.

IMO, an anamorphic lens is only a good purchase if you are shooting commercially and want the best possible anamorphic 16:9 image on a camera that has poor in-camera 16:9 while putting up with the inconveniences. These lenses are hard to set up and are not zoomable. So, you will need to shoot like film with a fixed focal length lens using dollies, cranes or stabilizers to move in or away from your subject.