The lamps looks and operates as any household lamp.
You walk into a room, flip the switch and you have light.
When the power is cutoff as a result of a power failure the lamp continues to burn using a built in battery as a source of energy. During the power failure you can still switch it on and off like any regular lamp. When the power is back the lamp will recharge when the switch is on and the lamp is burning.
Your day to day lamp is also your emergency lamp operating from the same switch you flip on and off daily!