It depends on your file system. Some filesystems are CASE sensitive but typically JPG and jpg are the same thing.
JPG,GIF,Bmp
image
image
Tif , jpg , png & gif
.html is not an image file, so it can't be converted to .jpg unless the .html file has images in it, in which case you would show extensions and then click in the name box and change .html to .jpg
Show extensions and then click in the name box and change .jpg to .html you will then be able to open your image file with your internet browser.
Most common graphic file extensions are: .jpg .jpeg .png .gif (for animated images)
Videos and moving pictures differ in coding methods. Moving pictures have file extensions like .jpg, while videos have file extensions such as .mp4.
"Jpeg" and ".jpg" are the same thing. The only difference is that most people prefer to say "jpeg" rather than "dot J.P.G."
The file extensions .jpg and .bmp do not support transparencies and are the most widely used.
Just change the extension (Rename).There is no difference between jpg and jpeg as file types ot kind of information they contain.
JPG is an image file format, while KB usually refers to storage space required. There actually is a .KB file format which is rarely used. It is some kind of keyboard script file. I doubt this is what you are dealing with, however.