SDXC cards are SD cards but with a much higher capacity and faster processing speeds. They have a maximum capacity of 2TB (Terabytes).
This camcorder's memory card type (SDXC) is actually the best supported memory card type across all video cameras that were released around the same time as the HC-WX979.
A MicroSDXC memory card is the worst supported memory card type across similar types of camcorder.
SDHC cards are DS cards with a higher capacity of up to 32GB.