Where additional lighting is unavailable or impracticable, flashlights provide a portable, temporary light source. These rechargeable or battery-powered flashlights can be brought wherever light is needed to illuminate dark or dimly lit places. Emergency lighting, nighttime navigation, maintenance work, and security patrols are all popular uses for them. From pocket-sized penlights for close-up activities to high-output lanterns for area lighting, flashlights come in many shapes and sizes.