In addition to load and save data on cassette tape, it’s also possible to use a 5¼” floppy drive together with your Commodore 64. Simply buy a Commodore 1541 floppy drive.
With the Commodore 1541 it’s possible to load and save your data to a Floppy disk, but even with this floppy drive, it’s still slow – but maybe a bit faster that the Datassette!