What are common methods for including a touchpad in laptops?

Including a touchpad in laptops often involves various methods, with the common practice being a combination of built-in and external connections. The touchpad is typically integrated directly into the laptop's chassis, which would fall under the built-in category. This integration allows for a seamless user experience and improves the portability of the laptop since the touchpad is always available without needing external devices.

Additionally, touchpads can also support wireless connectivity, such as Bluetooth, allowing users the flexibility to connect additional peripherals without taking up a USB port. However, in the context of this question, the inclusion of both built-in and USB methods as standard practices is particularly relevant.

USB connections may refer to external touchpads that can be plugged in when additional functionality is desired, catering to situations where a built-in touchpad may not suffice, such as for users needing specialized features or for portability in desktop setups.

Thus, the correct choice reflects a comprehensive understanding of how touchpads can be integrated into laptops, emphasizing both the necessity of a built-in touchpad for convenience and the inclusion of USB connections for versatility.