The Commodore 1541 Disk Drive allowed the use of floppy disk, rapidly speeding up load times in comparison to Tape based software. A C64 Floppy Disk had a whopping 170Kb of storage space per side. Often people used a 'Disk Notcher' or Hole Punch to enable the second side of the disk to be used.
A lot of software, games, and utilities were released on disk format for the Commodore 64, and you can still find a wide range available, both in physical format, and in online archives. Many people 'copied' disks, and thus there's a load of C64 Disk Collections out there that are made up vasty of copies. Whilst this was seen to be illegal, it was a common practice.
Today you can still purchase Disks for the Commodore 64 Be wary that being a magnetic medium, the age of these disks tends to produce a small failure rate. Try to find Disks in great condition, still in the box, in original format.
COMMODORE 64 SHOGUN CIB TESTED 525 5 FL...
TRAILBLAZER COMMODORE COMPUTER 64 128 C6...
COMMODORE 64 KIKSTART OFF ROAD SIMULATOR...
KARATEKA FOR COMMODORE 64 128 C64 DISK T...
COMMODORE 64 FLOPPY DISK GAME LORDS OF C...
SEGA OUT RUN GAME C64 DISK COMMODORE 64 ...
EXOLON COMMODORE 64 C64 GAME DISK HEWSON
COMMODORE 64 USER GUIDES DEMO DISK SOFTW...
COMMODORE 64 C64 INVADERS OF THE LOST TO...