SCADA is the centralized system that controls and monitors entire websites. All control actions are almost all automatically performed by remote terminal units or by programmable logic controllers. All parts of the SCADA system control one separate function like for example the PLC controls the flow of cooling water.

Data starts to flow in at the PLC or RTU level which are status reports from equipment. Data is formatted in ways so the control room can make quick supervisory decisions to override of adjust some parts of the system. Some threats that come with the system are that they are big potential targets from cyber terrorism and cyberwarfare attacks. There are two major threats one is the possibility of unauthorized access to software, either if it is intentional changes by a human or virus infections. The second major threat is packet access to network segment that host SCADA devices. Threats to critical infrastructure includes earthquakes, human activities, volcanic eruptions, and extreme weather. They protect it by fortifying physical security by making something more tuff so it can withstand harsh weather and putting in physical security like passwords or scan card. A person can do a lot of damage from just getting in to the physical place so, physical security is the most important role in protecting from humans. For internet security SCADA uses WAN protocols like the internet while, using cyber security techniques and standard protocols.