The USB-C to USB Adapter lets you connect iOS devices and many of your standard USB accessories to a MacBook with USB-C port or MacBook Pro with Thunderbolt 3 (USB-C) ports.
The USB-C Digital AV Multiport Adapter lets you connect your MacBook with USB-C port or MacBook Pro with Thunderbolt 3 (USB-C) ports to an HDMI display, while also connecting a standard USB device and a USB-C charging cable.