RODS stands for Record of Duty Status. This is a log maintained by the driver and updated each time they change their status, such as driving or stopped (e.g. fuel stop, tire check, load check etc.).
While company policy may vary, the FMCSA only requires that drivers record the time and location of each stop.
ELDs can maintain RODS automatically based on the GPS location and movement of the truck.
See also: ELD, HOS