A magnetic field is an invisible area around a magnet where magnetic forces can be felt. It is created by moving electric charges, such as those found in electrons. The strength and direction of a magnetic field can be represented by lines that spread out from the magnet's poles, showing how the force changes with distance. Magnetic fields are essential in various applications, including electric motors, generators, and MRI machines. They also play a crucial role in Earth's environment, helping to protect the planet from harmful solar radiation by deflecting charged particles from the sun.