Anamorphic Widescreen

Okay, I''ve read the Ultimate Guide to Anamorphic Widescreed DVD (for Dummies!) three times and I still don''t get it... The actual image on the DVD is a 4x3 image that appears stretched horizontally, right? As the Ultimate guide claims: "The ''squished'' image recorded on the disc (seen at top) is sent directly to the TV, which stretches the video signal horizontally until the correct aspect ratio is achieved." Uhm, hello? It stretches the signal horizontally? Correct me if I''m wrong, but if you stretch the image horizontally, that would degrade the picture quality immensely. Just look at a digital TV''s zoom feature: it stretches the image horizontally and vertically to make it fill the screen, but it looks terrible. What''s the point of anamorphic if all it does is just stretch the image horizontally just like the zoom feature does? The only advantage I see is that it doesn''t need to stretch it vertically as well. What am I missing here?