How can one Bitcoin address be associated with mulitple IP addresses? I'm new to Bitcoin and I'm having trouble understanding the concept of "address". I understand that an address is created when you want to send or receive bitcoins from someone. You create a bitcoin address and you give that address to someone so that he or she can send bitcoin to that address and you'll receive the payment. 

However, how can a bitcoin address be associated with multiple IPs? For example: https://blockchain.info/address-relayed-ips/15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC

This bitcoin address is connected with multiple IPs. I know that many bitcoin users advocate that we shouldn't reuse addresses. There is no way that someone else can just "pick up" the address that we just abandoned, since addresses are generated randomly. Then how is it possible that an address can be used in different IPs? Is it because the associated IPs include the IPs from which it has received payments?
A bitcoin address is not based on or tied to a network address, they are completely different.

Think of the Bitcoin address as a bank account number and the IP as a telephone caller ID. When you call your bank from different phones they'll see different caller IDs but you'll give them the same account number each time. They can write down the caller ID if they're spying on you, but that doesn't have anything to do with the account number other than the fact that you yourself are using both.

Likewise an observer can watch you sending transactions to the network from your IP address, and if you use the same Bitcoin address more than once they can see your sending IP address each time (unelss you use Tor...). But that doesn't have anything to do with the Bitcoin address other than the fact that you yourself are using both.