what is a 12/12 grow??

what do people mean when they say they grew a plant from seed to fininsh in 12/12 and what is it when some one says there plant auto growed or some shit like that??

12/12 means 12hours light 12 hours dark straight from seed, and auto means the plant flowers on its on, usually takes about 8 t 9 weeks start to finish on 20 hours light 4 dark or 24 7 light

means that it will be in flowering photoperiod since seed

Don't even think of 12/12 for veg go 24/7 if you can or 18/6 if you wanna save a little on the juice!
Veg would take a lot longer vegging!