+1^^ to
@wittaj 's response.
A USB cam is likely a "web cam", you'll want an "IP" cam that receives it's power and communicates the data over its Ethernet cable.
Known as "POE" as
@wittaj mentioned, it stands for "Power Over Ethernet".
If just one camera you generally use a
POE injector that plugs into 120VAC and converts it to the approx. 48 to 52 VDC to power the cam.
In the 4 twisted pair Ethernet cable, 2 pairs are for the IP cam's data and 2 pair are to supply DC power to the cam.
Insure the cam's POE spec and the POE injector are both 802.3af compliant.
Use pure copper (not CCA / Copper Clad Aluminum) CAT-5e or CAT-6 cable and you should be able to power that camera easily 200 ft. from the POE injector at the 120VAC outlet.
There's a LAN port on the POE injector to connect to your network and your means of live streaming.