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 64 128 1541 1571 ALIGNMENT PRO...
LOT OF COMMODORE 64 FLOPPY DISK SOFTWARE...
TALES OF THE UNKNOWN VOL 1 THE BARDS TAL...
FAST SHIP COMMODORE 64 DISK LOT 3 OF 15 ...
COMMODORE 64 FLOPPY DISK SUBSCRIPTION SE...
ATARI 8 BIT COMPUTER PQ THE PARTY QUIZ G...
COMMODORE 64 10 FLOPPY DISK GAMES LOT
COMMODORE SUPER SNAPSHOT TESTED WORKING...
COMMODORE 64 128 THE PRINT SHOP FOR C64 ...