An IP camera is a camera that can be directly connected to a network (local or internet). This can be achieved using an Ethernet cable or (depending on the camera) via a wireless network (Wifi / IEEE 802.11b/g/n).
This is different than the conventional PC cameras that can only be used when the PC to which they are connected, is turned on.
IP cameras work independently from a PC and have their own built-in processor and can be approached by the network by using an internet browser. This makes it possible to operate and configure the camera remotely.