Is Bit Coin a Fungible Token?

The block chan inasense is a perfect digital registry. Whence you put data in there, it can't be taken out. So it's very good for establishing ownership of things. And bit coin is the first fungible token in that in the sense that bid coins are interchangeable with each other so they are called fungible. But no one can steal my bit coin once it's in theree secured by the network and by my private key. I'm not in a position yet where i can really articulate anates and that whole phenomenon yet because i don't fully understand it myself yet.