Script Variables
ObjectNet provides the facility to automatically synchronize variables across the network. This can be very useful to avoid a lot of events to keep objects updated.
Network Variables are synchronized from Active to Passive instance, this means that a variable modified on the Active instance will be sent over the network and applied on all Passive instances.
Script Variables tap can be open/close by clicking on the variables icon.
A list of all variables on the main NetworkObject component shall appear and you can enable/disable any script variable.

By flagging the check box you can enable variable synchronization across the network.
Network Variables is available only for scripts inherited from NetworkBehavior, if the script was not inherited from NetworkBehavior is not possible to synchronize variable values ( see Network Variables).
Check Variables DeliveryModes: to learn more about the diffrence between Reliable and Unreliable variables and when to use them