A microchip is a tiny piece of material that contains electronic circuits allowing it to store a lot of information. Many dogs have microchips so their owners can easily find them if they get lost.
Microchips are made by etching an electronic circuit into a bit of silicon the size of a grain of rice. This tiny device can hold computer memory and processors, or be used to conduct electricity. You almost certainly use things that contain microchips just about every day, including calculators, bank ATMs, certain ID cards, cell phones, and televisions. The word microchip was coined in the 1970s from micro-, "small," and the electronics term chip.