JPEG Vs. JFIF

So everyone knows a JPEG file by it’s extension, .jpg. But look at it with the file tool, and you get something like this:

findcover.jpg: JPEG image data, JFIF standard 1.01, aspect ratio, density 1x1, segment length 16, baseline, precision 8, 1600x900, frames 3

“JPEG image data, JFIF standard 1.01”. So, what exactly is the difference in these two? And furthermore.. why are we using the wrong name for the file format in the first place?