Any storage medium that utilizes magnetic patterns to represent information is considered magnetic media. Good examples of a magnetic media and magnetic storage is a tape drive, floppy diskette, and hard drive.
Above is an example of the read/write head inside a hard drive. The electromagnetic write head polarizes tiny sections of the hard drive so they face up or down ("North" or "South") to represent the binary digits 1 or 0. Once the information has been written to the hard drive it is read by the read head, which detects the polarization of each section of the drive to understand the data that has been written.