they both have a postive charge and when you build up that current of electricity and you touch something metal or something that will conduct that electricity you get a shock which is why when you wear socks around the house adn you touch something after youve been rubbing your feet on carpet you get shocked. same principle with lightning. there is a lot or portons in the air and they come together with a charge and when they get charged enough you get lightning. i dont really know how to explain it im sorry but i hope it helped a little.