Apart from a kiss being an act of simply pressing one's lips against the lips or body parts of another or of an object, there are studies that depending what you kiss the brain steps it up a notch.
A kiss can express sentiments of frienship. greeting, respect affection, love and passion.
So in Freindship and Greeting, a kiss is a formal or symbolic guesture, as in family and friends kissing each other in greeting;
in Respect and Affection, a kiss is a ritual as in the case of a bride and groom kissing at the conclusion of a wedding.
The above four sentiments are used towards our family and friends in many cultures, but where it get interesting is:
A Kiss in Love and Passion
Tingling sensation down your spine and into the toes, and sometimes if it's the right kiss, that part of you, the inner most secret part, moistens, heats up and throbs in the rhythm of your heart.
Then we have theVampire Kiss:
But this kiss will inflict on you more pain than a bee's sting, a pain you want and somehow expected. It is as if you are about to suffocate, yet, nevertheless, you want more, it’s more than an aphrodisiac, sending pulsing pleasures deep inside of you. A drug or some kind of poison will make you surrender to the pleasure and the pain of the Vampire kiss. You will pass out from it and when you regain consciousness you will wonder why you have not died.