ASA5505 Cryto Map sequence number explanation

I am setting up a site-to-site VPN between an ASA550 and a 1721 and have a question on the ASA config. I am configuring the crypto map below but don't understand the sequence numbers. I read the Cisco command reference explanation but it's still not clear to me. Should I configure as such:

crypto map VPN_MAP 10 match address TRAFFIC_TO_REMOTE
crypto map VPN_MAP 10 set peer 171.22.55.2
crypto map VPN_MAP 10 set transform-set AES_SHA

or like this:

crypto map VPN_MAP 10 match address TRAFFIC_TO_REMOTE
crypto map VPN_MAP 20 set peer 171.22.55.2
crypto map VPN_MAP 30 set transform-set AES_SHA

What's the difference?