Is there a difference between jpg, jpeg and png?

Question

JPEG

Downloading files through a Python script, graphic files, I accidentally discovered that if you incorrectly specify the format for the downloaded file to the script (for example, replace jpeg with jpg or png), then the file still remains working. In this case, the size of all variations remains the same. Hence the question: how is it done and is there really a difference?

Answer 1

The name of the file does not affect anything at all. The format is defined at the beginning of the file itself and serves as an instruction for interpreting the subsequent set of bytes. Of course, there is a fundamental difference between these formats.