WebP is a next generation image format that offers much better optimization than JPG, resulting in lower file sizes and faster loading pages.
When you upload your JPG images to the WideRange admin, the WebP image files are automatically generated, so you don't have to do anything special.
Your website displays the WebP images by default* (for the performance gains); however, you have the option of displaying the JPG image instead for certain photos if they suffer image quality degradations in the WebP format.
* Sometimes the WebP image version may have a larger file size than the JPG, and in that case the JPG is automatically chosen for display (regardless of the WebP setting).
You can read more about WebP images and see examples of how they compare to JPG images here.