I know what it does, but what does the name mean? Is it a acronym? In one sentence, how would you explain vcgencmd to someone new to Linux?
vc stands for VideoCore.
gen might stand for general.
cmd for command.
As guessed from this comment
/* Initialise general command service. Returns it's interface number. This initialises the host side of the interface, it does not send anything to VideoCore. */
vcgencmd.h as seen here and the fact that this tool is used to issue a broad range of general commands to the VideoCore.
A more friendly link vcgencmd
The following are commands I find useful
vcgencmd get_config int vcgencmd get_config str for src in arm core h264 isp v3d uart pwm emmc pixel vec hdmi dpi ; do \ echo -e "$src:\t$(vcgencmd measure_clock $src)" ; \ done for id in core sdram_c sdram_i sdram_p ; do \ echo -e "$id:\t$(vcgencmd measure_volts $id)" ; \ done vcgencmd get_mem arm && vcgencmd get_mem gpu
See https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=147781&start=50#p972790 for interpretation of get_throttled