Basically, the Touch gives you a means of interacting with, and thus steering or controlling, the visual contents of the headset. Focusing on something, reaching out, making selections or navigating a journey…
According to Wikipedia:
They consist of a pair of handheld units for the left and right hand, each containing a joystick, buttons, and two triggers – one for grabbing and one for shooting or firing. The controllers are fully tracked in 3D space by the Constellation system, so they may be represented in the virtual environment. Oculus Touch also features a system for detecting finger gestures made when holding the controllers.
So, what’s inside the controllers? The iFixit team writes:
Each Touch controller packs 24 IR LEDs for tracking, three buttons, two triggers, a joystick, and a “thumb rest” capacitive sensor. This combination of inputs far outpaces the Sony Move or HTC Vive controllers, allowing the Rift to track thumb, forefinger, and hand position. The Touch controllers share some silicon with last year’s Steam controller, and some aesthetics of an Xbox controller — but it’s a beast all its own.
Some teardown highlights identified by the team include: an easily-accessible AA battery, which itself can be swapped for a rechargeable one, and only T5 and T6 Torx screws are used, simplifying screwdriver selection.
Overall, though, the Touch controller only scores a 5 out of 10 on the iFixit reparability scale, due to “intense adhesive, and a complex construction”.
Specific downsides include: “the joystick, button bases, and battery connections are soldered directly to a board and require soldering knowledge to repair”, and “navigating through the tabs, adhesive, and hidden screws is not intuitive and could result in damage during disassembly”.
For comparison’s sake, the Apple Watch Series 2 earned a 6 out of 10, the iPhone 7 a score of 7, and the Goggle Home Assistant a score of 8.
See also: Tearing down the Goggle Home assistant