## file.jpg or file.JPG or file.jpeg -- Does it matter?

### JPG or jpg

- Yes. If your filename is "beach.JPG" then you need to reference it as "beach.JPG" -- having "beach.jpg" in the URL won't work!
- No. As long as the case of your filenames match the case in your URL references you'll be fine.

### jpeg or jpg

- No. Media types can be mapped to multiple file extensions, so generally either `picture.jpg` or `picture.jpeg` filenames are fine.
  And for JPEG images, the media type (also known as MIME type) is "image/jpeg"