When the rainfall takes place, the resulting water will either infiltrate into the soil or it will flow over the land surface and constitute rainfall runoff.
The amount of water that can infiltrate into the soil depends on a number of factors including, the intensity of rainfall, permeability of the soil surface, presence of vegetation, topography, etc. The infiltrated water may ultimately reach the groundwater. This water is generally harvested by using bore-wells.
The runoff takes place when the land has some slope. The water moves from an area of higher elevation to a region of lower elevation. If the land surface has no slope at all, the runoff will not take place and waterlogging will be the result. The surface runoff, ultimately, ends up in the surface water sources, such as rivers, ponds, lakes, swamps, etc.
Hope this helps.