In British English, a torch is a small portable light powered by a battery, exactly what American English calls a flashlight. In American English, a torch is instead a stick with a flaming end, the kind carried in a procession. So a British torch and an American flashlight are the same object, but a British torch and an American torch are not.
The core difference
Torch is the British word for a battery-powered handheld light, while flashlight is the American word for that same device; American English keeps torch for a burning flame on a stick.
- torch — British: a small portable battery-powered light: She grabbed a torch before heading into the dark basement.
- flashlight — American: a small portable battery-powered light held in the hand: She grabbed a flashlight when the power went out.
How to tell them apart
The word torch comes from Old French torche, probably from a Latin word for a twisted bundle of straw or fibre soaked in pitch and set alight, which explains why American English still uses torch for a flaming stick rather than a battery light. Flashlight is simply a compound of flash and light, describing the beam the device throws out.
The mix-up tends to show up in instructions or product listings written for one market and read in another: a British reader told to grab a torch will reach for a battery light, while an American reader told the same thing might picture fire. Note also that torch has an unrelated verb sense in both varieties, meaning to deliberately set fire to something, as in rioters torched several cars.