The Compute Module IO Board V3 is a development kit for those who wish to make use of the Raspberry Pi in a more flexible form factor, intended for industrial applications. The IO Board V3 is made for developing with CM3, CM3L, and CM1.
The Compute Module contains the guts of a Raspberry Pi 3 (the BCM2837 processor and 1GB RAM). The accompanying IO Board is a simple, open-source breakout board that you can plug a Compute Module into. The board hosts 120 GPIO pins, an HDMI port, a USB port, two camera ports, and two display ports. Designing the Module into a custom system should be relatively straightforward as all the tricky bits have been put onto the Module itself, and you have the freedom to add extra components and place parts exactly where your product needs them.