Most of the SBCs are supported by fairly standard Linux distributions: Debian/Armbian or Fedora; you just boot from the approriate image on an SD card. Some SBCs have eMMC storage and/or a M2 connector, so you can either keep running off the SD card or transfer the image to that storage.

The value proposition of using SBCs is in their embedded connectivity; in addition to standard USB/network/HDMI ports they tend to have built-in connectors for:

* MIPI input, for video cameras

* MIPI output for LCD panels

* i2c and SPI for weird peripherals (accelerometers, temp sensors, etc)

* i2s for sound

* GPIO and timers/PWM for custom peripherals like motors/servos, contacts, programmable LEDs etc.