What minimum equipment is needed to program the Freematics Vehicle Data Logger?
"Arduino as ISP" refers to using an Arduino board in place of a USBasp.  It involves loading a specific sketch onto the Arduino then using the SPI port (and a few other pins) as the programming interface to the target.

It is most often used to program blank chips for use in breadboards by people who don't have a USBasp.  Great for moving your project from the Arduino board to a breadboard without having to buy a hardware programmer.