What is the primary function of a trackpad?

The primary function of a trackpad is to control cursor movement on a computer screen. It acts as a pointing device, allowing users to navigate through the graphical user interface by sliding their fingers across its surface. The movement of the user's finger translates into the movement of the on-screen cursor, enabling tasks such as selecting items, dragging, scrolling, and other interactions.

While some of the other options describe functions of various devices or technologies, they do not pertain to what a trackpad specifically does. For instance, measuring angles and rotation is generally the role of sensors found in devices like gyroscopes. Displaying pixels pertains to screens and visual output devices, which are responsible for rendering images and text. Converting touch input into digital signals is a broader function associated with various touch-sensitive devices, not limited to trackpads, but which ultimately feeds into how the trackpad communicates with the operating system to control the cursor.

In summary, the trackpad's key role is the direct manipulation of the cursor, making it an essential input tool for users navigating electronic interfaces.