What does "watering when the soil is dry and then wet" and "watering alternately between dry and wet" mean?

See dry and wet

Watering when the soil is dry and watering when the soil is wet is a common principle, which is mainly applicable to neutral flowers currently cultivated in ordinary households. "Seeing the soil is dry" means that after watering once, wait until the soil surface turns white and the moisture in the surface soil decreases before watering for the second time. Do not wait until the soil in the pot is completely dry before watering. "See wet" means watering thoroughly and until water seeps out of the drainage holes in the bottom of the pot. Do not water "half way" (that is, wet on the top and dry on the bottom), because the roots of a thriving plant in a pot are mostly attached to the bottom of the pot, and watering "half way" is actually equivalent to not watering.

Dry and wet

This means that you should wait until the entire pot soil is basically dry before watering, and you should water it thoroughly. Water it thoroughly when it is dry, that is, alternate between dry and wet.