The word "cái gương" in English is "mirror." A mirror is a reflective surface that people use to see their own appearance. Most mirrors are made of glass with a shiny metal coating on one side, which allows light to bounce back and create a reflection. People often hang mirrors in bathrooms, bedrooms, and hallways because they are useful for getting dressed, fixing hair, or applying makeup. In addition to their practical uses, mirrors can also make a room look brighter and larger by reflecting light and scenery.

Mirrors have been used for thousands of years. In the past, people used polished stones or metal surfaces as mirrors before learning how to make glass mirrors. Today, mirrors come in various shapes and sizes and are commonly found in homes, cars, and even public places like elevators and offices. Designers also use mirrors as decorative items to enhance the overall interior design of a space. For example, adding a large mirror to a small room can create the illusion of more space and make the area feel more open and inviting.

Besides personal grooming and interior decoration, mirrors have many other important functions. In science, mirrors are used in telescopes to observe stars and galaxies far away from Earth. Doctors use small mirrors to examine parts of the body that are otherwise hard to see. Drivers use rearview mirrors to see what is behind them and drive safely. Whether for daily routines, scientific research, or ensuring safety, mirrors play a significant and versatile role in our modern lives.