sACN is generally used in Multicast. Art-Net is generally used in Broadcast or Unicast.
Lighting control systems that transmit Unicast traffic over an Art-Net or sACN network
In a Unicast network the controller must know the static IP address of all devices to send traffic to. All devices need to be in the same IP range as the controller and in Static IP mode. The receiving devices will only listen for traffic addressed to them. This allows for devices to ignore traffic that doesn't apply to them and allows for lower processor overhead on the device since it doesn't have to decode the entire packet to find out what it needs to do.
All devices on a Unicast network must have static IP addresses assigned to them
Lighting control systems that transmit Broadcast traffic to over an Art-Net network
In a Broadcast setting the controller is sending out the entire Art-Net packet to every device on the network. Every device on network needs to decode the entire packet to find the information that applies to it. Advantages are that the user doesn't need to keep track of the IP addresses of devices on network.
Devices on a broadcast network can have static IP addresses or use DHCP for their address assignments
The main disadvantage of Broadcast is that the processors on receiving fixtures/devices need to decode the entire Art-Net packet for all IP addresses in your subnet. This may overload weaker processor units causing erratic behavior on connected devices.
Lighting Control systems that transmit Multicast traffic over a sACN network
Multicast is a hybrid of broadcast and unicast. The controller on the network sends out the changes to the sACN packet over network and the sACN packets from the controller are divided into DMX universes, so devices on the network only listen for the universe that they are subscribed to. Advantages are the user doesn't need to keep track of IP addresses for devices on network and bandwidth usage more efficient, allowing many universes of control over an unmanaged network.
When using Multicast devices on the network ignore their IP address settings and only listens to the Multicast IP address (this mode is usually plug&play for your devices)
Regardless of the type of system deployed Quasar Science recommends having a DHCP server on the network to distribute IP addresses to devices that are not configured with static IP addresses.