If you lost the key, someone else may have the access to your lock. With combination locks, it requires you to memorize the correct numbers or pattern to turn the lock and then to access it. This is great for people who always lose their things. These kinds of locks are mainly found in padlocks and briefcases. The lock may be somewhat like a dial design, which contains disks inside the lock and has to be rotated using the dial to get to the right combination.
Padlocks deal with a combination disks and uses the combination lock design.
The physical exterior of a combination lock is having a dial, which contains numbers in numerical order. There would be a mark on one side of the lock signifying what number the lock is on. The dials will be turned multiple times clockwise and counter- clockwise to open the lock. To look at the inside of the lock, it will contain a number of discs, usually three. Each disc contains a little part cut out from the edge.