tc_position attributes

what is these fields in position table
workMode,
gpsStatus,
hours,
event

any body can help me?
{"priority":0,"sat":13,"event":21,"ignition":true,"motion":true,"workMode":1,"rssi":3,"io200":0,"gpsStatus":1,"pdop":1.1,"hdop":0.8,"power":14.381,"io24":0,"battery":3.954,"io68":0,"distance":693.63,"totalDistance":95146.78,"hours":344264920}