If you were wondering what the difference between a style and a preset in Capture One (I’m on the latest version Capture One Pro 20 (13.1.1)) I’m about to tell you.
A preset is specific adjustment for a single tool. You can make a preset for something like Vignetting where you find yourself commonly applying a -0.5 amount a lot. You set the Vignetting amount to what you want like 0.5 or -0.75 then click on the three lines icon (they call it the hamburger icon) and click Save User Preset. You give it a name like Minus 0.75 or Plus 0.5. Once saved you can quickly apply it to your current image by clicking on the hamburger icon again and picking the preset you want. Note that some of the tools come with standard set of presets that you might want to explore. Check out the Levels presets.
A Style allows you to save the current state of multiple tools. If you have a look or color grade for a particular shoot you can save the state of multiple tools. This makes it quite quick to apply a look to multiple images quickly and consistently. In this particular case I adjusted the above image and really liked the color and contrast so I created a style. Creating a style gives you the option of which tool changes you want to incorporate into the style.
I then edited another image using that style to create a very similar feel. Makes it quite easy to get a cohesive feel to your images.
Once you have applied a style (or more than one since that is also allowed) you can make further adjustments to any of the tools to hone in on the image that you saw when you made the image. In this image I added a little more contrast.