The GZ-HM30 supports an SDXC compatible memory cards which is better than most camcorders of this spec and age. Most video cameras that have been available for a comparable time to it support an SD compatible memory cards. This video camera also supports an SDHC compatible memory cards. SDXC cards are SD cards but with a much higher capacity and faster processing speeds. They have a maximum capacity of 2TB (Terabytes).
An SDXC compatible memory cards is actually the best supported memory card type amongst all video cameras that came out around the same time as the GZ-HM30.
The worst supported memory card type amongst similar types of camcorder is MicroSD (Transflash).
SDHC cards are DS cards with a higher capacity of up to 32GB.