Is paypal a type of bank?

When we put money into our paypal account, it is removed from our bank account. Through the internet we can see the balance of the money we have in our paypal account.

Now, does this mean that paypal has it’s own money vault? If not, where does our money go when removed from our bank account?

If it goes into the paypal’s bank account, then i would assume it works as a ‘pay me now, and i’ll pay you back later this same amount’. But then, wouldn’t paypal pay taxes on these funds that are transferred into their account?

But if this is not the case, then paypal is essentially an online bank, with all the same rights, correct?