Mrscramer,
Static IP address means the Internet Provider (ex: Telus, Rogers, or Shaw) give the customer a specific IP address that they will always use.
Dynamic (DHCP) IP address means the customer grabs a random IP address from Internet Provider's "hat" so to speak. The customer will use that IP address for a set amount of time (ex: 24hrs or longer) before they have to grab another random IP address from the Internet Provider's "hat".
For Hotels, Public Wireless, Home Networks, etc... the Internet Provider gives them an IP Address (either Static or Dynamic). The Hotel (for example) piles as many guests as it can on the same IP address. So in your Hotel reference in another post, any Agoracom user at the hotel would indeed "appear" to be the same user, because the same IP address is being shared. Think of it as car pooling with IP addresses instead of car's.
I suspect this will be seen a lot during the AGM, since people will be at the same hotel.
Hope that makes sense.