There are three easy ways to connect a phone to a projector:
Cable – Nearly every iPhone and Android device has a video output port. Most projectors still use HDMI as their standard input port, so a simple adapter from either the USB-C connector on an Android or HDMI connector on the iPhone will enable you to get the cable connected – all you need to do is change the source to start screen mirroring from your phone to a projector.
Casting – If you have a Chromecast or an Apple TV, you can wirelessly connect to your projector and mirror your screen. You will need to be on the same network as the receiver, then use your built-in screen mirroring to send it to your projector. This is a nice option when you want to show photos or videos on your device, or for occasional use.
Wireless Presentation System – For business or education use, a wireless presentation system is faster and more secure than the other two options. The best models enable you to plug in a button to your phone or tablet and start sharing instantly. Others use either a dedicated app installed on your phone or Airplay to share the screen. While they are more expensive, the best models encrypt the transmission, so sensitive information can’t be wirelessly captured and seen from curious people in the area.