The Control Panel in Windows is
a collection of applets,
sort of like tiny programs,that can be used
to configure various aspects of the operating system.
The Control Panel , in the context of Windows,
is a software module used to perform
administrative and management operation system tasks
and/or provide access to specific software features.
The Control Panel is used to configure and manage
almost all aspects of Windows

Example:

keyboard and mouse functionality.
Users and Passwords
Power options
Network setting
Desktop background
display settings
Remote desktop-virtual control panel
Vpn tools
System security settings
Input devices & Network tools (network devices)
changing accessibility Options
sound settings
Hardware and Software options
Insatalliation and Removal of programs
....and much more

List of Control Panel Applets in Windows