A capacitor is an energy storing device, and so is a battery. The battery stores its charge in chemicals, but the capacitor does so in its electric field. If you connect a high power battery to something like a steak, or a watermelon, it will not do much. But when you do the same with a capacitor, the results can be amusing, or even terrifying, as the capacitor can release charge in much less than a second, unlike a battery that releases charge slow and steady.
The video shows a small 2000 Volt capacitor blowing bits of a sausage and other tiny things, but the same capacitor could do a steak no significant damage. So TheBachyardScientist picked up four 25uf capacitors rated at 20kv from a lab that simulates effects of lightning on materials. The video mainly shows what would happen if a lightning bolt struck a watermelon that too in slow motion, shot with the Chronos 1.4 High-Speed Camera.
Ever fancied if you could cook your steak with a lightning bolt? Well, you can if you want it reverse seared and inedible. Here is the video. Enjoy.