question

i'm not a religous person. i choose to exclude religion from my life. that being said, i'm curious about how the pope was buried today. maybe someone with a more thorough understanding of the catholic religion can shed some light on this.

the pope was buried today in 3 layers of coffin. 2 wooden coffins, with a zinc coffin between them. It is then place inside a marble crypt. from what i can gather through online articles, this is to create an airtight situation in order to preserve the body of the pope.

can someone tell me what's the purpose of preserving the body?