When an image is saved as a JPG, what happens to the layers in the image?

When an image is saved as a JPG (JPEG), the layers in the image are flattened. This means that any separate layers, such as those used in graphics creation software like Photoshop, are combined into a single layer. Flattening occurs because the JPG format is designed for simplicity and efficiency, typically used for photographs and images where a single composite view is desired.

The JPG file format does not support layers; instead, it compresses the image into a single bitmap representation. This compression can help reduce file size but sacrifices the ability to edit individual layers later on. Therefore, when saving an image in JPG format, any complex editing features present in the original layers are lost, and the final image is rendered as a flat, single-layer image.