Sticky Keys is a built-in accessibility feature in Windows, macOS, and other operating systems that helps people who cannot physically hold down two or more keys at once, often due to limited hand strength, dexterity, or the use of a single finger or mouth stick to type.
With Sticky Keys enabled, pressing Shift and then C separately produces the same result as holding Shift while pressing C. Keyboard shortcuts on a website that require true simultaneous key presses, rather than relying on the operating system’s own modifier handling, can be unreliable for users who depend on this setting.