Summary
How to connect an iPad, iPhone, MacBook, MacBook Air, MacBook Pro, or Microsoft Surface Pro in a generally-scheduled classroom space.
Body
Identifying the connector on your Device
Apple has a very diverse range of products and adapters being used by these devices. The easiest way to start finding the right adapter for your device is simply to explore it. Ports for connectivity are usually located on the sides of the device (MacBook) or the bottom edge of the device (iPad or iPhone). Microsoft Surface Pro devices typically have these on the side.
Mini DisplayPort
Used on older MacBook devices. Also present on Microsoft Surface Pro devices.
Thunderbolt v1 or v2 (same connector)
Used on more recent MacBook devices.
Thunderbolt 3 or USB-C
Used on the most recent MacBook devices and iPhones. Starting to be used on some smaller form-factor PC laptops as well. For more information on the video output capabilities of certain USB-C connectors, see this article.
Lightning
Used on some older iPhones and iPads. (Note the difference from USB-C. Lightning does not have any circuitry in the middle of the connector.)
Identifying the connector needed by the A/V system
HDMI is the preferred connector for A/V systems. Please see this article for information on spaces equipped with HDMI.
If the system is not equipped with HDMI, you must use a VGA connector. If audio is desired with a VGA connection, you must also connect the 3.5mm audio cable to your headphone jack.
Which adapter to use?