What do these pins on the Uno do? I've been wondering for a long time what these pins, labeled ICSP and blank, do.



I can't seem to find a diagram that explains them, so I've been wondering:


What are they for?
Are they GPIO, or do they do something special?
How can you use them?


Thanks for the help.
They're for programming, as well as carrying the non-select signals for SPI. The right one is for programming the main MCU, the left for the USB communication MCU. You should almost never need to use them unless you need to write a bootloader to a new chip or change the fuse or lock settings on them.