A laser is a device that creates an extremely focused beam of light by energizing atoms until they release photons in perfect unison. Unlike regular light, which scatters in all directions like a lightbulb, a laser beam stays tightly concentrated and can travel long distances without spreading out.

Scientists discovered how to make lasers in 1960, and they quickly became one of the most versatile tools in modern technology.

Lasers appear everywhere in daily life. The checkout scanner at a grocery store uses a laser to read barcodes. Laser pointers help teachers highlight information on screens. Surgeons use medical lasers to perform delicate eye operations with incredible precision. DVD and Blu-ray players read discs with tiny lasers. Fiber-optic internet cables carry information encoded in laser light at tremendous speeds.

Some lasers are weak enough to be safe when used properly, like the red dot from a presentation pointer. Others are powerful enough to cut through metal in factories. Scientists even use lasers to measure the distance to the moon by bouncing beams off mirrors astronauts left there in 1969.

The precision of laser light makes it invaluable whenever accuracy matters. Because the beam doesn't spread or fade quickly, lasers can accomplish tasks that ordinary light simply cannot.