DDNS (Dynamic DNS)
DDNS (Dynamic DNS) is a service that maps Internet domain names to IP addresses. DDNS serves a similar purpose to DNS: DDNS allows anyone using one of our surveillance systems access remotely, regardless of whether they have a static IP address.
Unlike DNS that only works with static IP addresses, DDNS is designed to also support dynamic IP addresses, such as those assigned by a DHCP server. That makes DDNS a good fit for home networks, which often receive dynamic public IP addresses from their Internet provider that occasionally change.
To sum up, you need to be able to access your DVR remotely over the Internet, there are three ways to go to know your IP address.
1) Ask your provider for a STATIC IP Address this is an IP address that does not change. It stays "static". This is the best way to go but may cost more from your ISP.
2) DYNAMIC IP address is what you are given from your ISP by default. Look it up (http://www.whatismyip.com) write it down and understand it does change from time to time.
3) DDNS Dynamic Domain Name System. You setup a remote website to receive the IP address from your DDNS service which can be setup in your DVR or Router.