Plastic is a synthetic material made from chemicals, usually derived from petroleum, that can be molded into almost any shape when heated. Once it cools, plastic holds its form, making it incredibly useful for everything from water bottles to car parts to computer keyboards.

Scientists discovered how to create the first true plastics in the early 1900s, revolutionizing manufacturing. Before plastic, people used materials like wood, metal, glass, and ceramic, which were often heavier, more expensive, or harder to shape. Plastic changed everything: it's lightweight, waterproof, and cheap to produce.

Today, plastic is everywhere. Your toothbrush, phone case, and backpack probably contain plastic. Doctors use sterile plastic syringes and tubing. Builders use plastic pipes for plumbing. Scientists even use plastics in spacecraft.

The challenge with plastic is that it lasts almost forever. While durability makes plastic useful, it also means plastic waste piles up in landfills and oceans. A plastic bottle you use for ten minutes might take about 450 years to break down naturally. This has led scientists and inventors to work on biodegradable alternatives and better recycling methods.

The word plastic can also describe something flexible or moldable, like when a sculptor works with plastic clay, or when someone talks about the brain's plastic ability to learn and change throughout life.