The C-series was a line of protomech droids created by Industrial Automaton and succeeding the B-series. Like the others in its line, it was created on the astromech schematic, but was built to meet an all-purpose droid demand.
C-series droids could perform both menial tasks- such as repairs and pack work -and higher positions such as chauffeuring on starliners and, the most broadcast of their abilities, their function as personal protocol droids.