There are three major types of sizes of floppy disks – 8 inches, 5.25 inches, and 3.5 inches. The 8 inches floppy disk was introduced in 1971, whereas the 5.25 inches was developed in 1976. However, the 3.5 inches was the most popular size out of the three.
IBM developed the 3.5 inches in 1984. These floppy disks had a total capacity of 720 KB and were widely in demand. Sony manufactured the 3.5 inches floppy disks, which saw huge sales during the 1990s and 2000s.