how is groundwater and runoff alike?

Question

in sixth grade science

Answer 1

If the ground/ soil cannot accept any more rain water (ground water) then runoff will occur. That is called saturation.
If the rain exceeds infiltration into the soil then runoff will occur. That's called pissing down with rain.
Runoff will also occur if the groundwater level is higher than the level of the actual ground. This is called a spring (discharge). If it is big enough it can be called a lake.

Answer 2

They're both water, and they're both likely from rainfall.