Strobe lighting are often associated with discos, but one of the most common uses for it is in fire alarm systems. Fire alarm strobes are combined with horns or sirens to grab attention, and warn people of a fire breaking out.
In a typical fire situation, smoke will quickly blot out the light and turn conditions dark and suffocating. So, strobe lighting are meant to be seen amidst the smoke and point people to the fire exits.
A typical fire alarm strobe is connected to the control panel, and is meant to go off when the smoke alarms or heat sensors trigger the panel. While the fire department will be alerted, this has nothing to do with the fire alarm strobe, whose sole purpose is to alert the occupants of the building to exit the premises as fast as possible.
Many early strobe models had transluscent lenses which were sometimes colored blue or red; much like police car or ambulance sirens, which are in fact, strobe lights as well. Due to new requirements of disability laws, it is now a requirement for fire alarm strobes to have clear lenses. Some buildings will still sport the older colored models though.
It should be clear that strobe lights are invaluable in grabbing attention in poor visibility conditions, like what happens during a fire. They also help in search and rescue operations in inclement weather. While the typical home fire alarm system may not require strobe lighting, they are certainly a must in any medium to large sized building that has a fire alarm system installed.