What is the difference between a Smooth Fox Terrier and a Jack Russell?

There are several differences between a Smooth Fox Terrier and a Jack Russell, although they may seem quite similar at first glance. 

The Smooth Fox Terrier has a sleek, smooth coat that lies flat against their body, giving them a more polished appearance. They tend to have a taller, more refined build, with a long, narrow face, a squared-off muzzle, and V-shaped ears that fold forward.

In contrast, Jack Russell Terriers have a more compact and muscular build, with a slightly shorter stature. Their coats can be either smooth, rough, or a mix of both, and they have a broader head with a more pronounced stop (the point where the muzzle meets the forehead). Jack Russells also tend to have a more energetic and sometimes more independent personality. Smooth Fox Terriers are energetic, too, but might be a bit more focused and less intense.

So, while both breeds share a lively, spirited nature and a love for adventure, their appearance, build, and sometimes even their temperaments set them apart.