There are several key differences between fire hydrants and fire department connections that are important to note. Fire hydrants are typically stand-alone units in public areas that are connected to the public water supply. They can be used by fire departments to quickly access a large amount of water for firefighting purposes. Fire department connections are multiple lines that act as a connection between a fire department and a building. These connections are installed by the fire department and allow them to quickly access the building's water supply in order to fight a fire. The lines are typically smaller than those used for hydrants, and the pressure of the water is lower due to the size of the lines. Additionally, fire department connections are usually only used for buildings that are monitored by a fire alarm system, allowing for a quicker response time in the event of a fire. Fire hydrants, on the other hand, are installed to provide water for public use and are not typically used for fighting fires.