What are the small red lights around the CCTV cameras?
CCTV stands for Closed-Circuit Television. These are used for video surveillance.
In broadcast television in that, the signal is not openly transmitted, but in CCTV may employ signal point-to-point (P2P), point-to-multipoint (P2MP), via mesh wired or wireless links. CCTV systems may operate continuously or only as required to monitor a particular event. Digital video recorders (DVRs) are used with CCTV, and recording may be kept stored in DVR for many years, with a variety of quality and performance options and extra features (such as motion detection and email alerts). Decentralized IP cameras, are equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation.
Those small red lights around the CCTV cameras are called IR LED or simply infrared LED. They're used to supply lighting for security cameras to see in dark and low light conditions which are turned off at day time. Through those small red lights, cameras can be able to capture images at dark by means of infrared.