Yes, you are correct.
You pull out the dipstick. The amount of oil on the dipstick show how high the level in the crankcase was, when the dipstick was still in. Usually there are two marks on the dipstick. If the oil is between those two marks, there is enough.
If there's no oil, or if the level is very low, then it might be below the bottom of the dipstick and it would come out dry. Starting the engine might wreck it.
There wasn't enough oil. It didn't come up to the bottom mark. But the bottom 1/8" of the dipstick was wet, so there was some oil. It is probably safe to start the engine and run it for a short time.