Following are the tree processes which help the plants to absorb water and minerals  from the soil.  

1. Diffusion: Soil water moves into the root hairs through the process of diffusion  from higher concentration to lower concentration as we put sugar in the milk and  the sugar molecules are evenly distributed in the milk and occupy inter molecular  spaces of milk.  

2. Osmosis: The cell sap and the cell walls act as semi- permeable membranes and  permeable membranes. The concentration of the cell sap is more as compared to  the water + minerals present in the soil. So the water and dissolved minerals  enters the roots by the process of osmosis.  

3. Active transport: Root hairs absorb water and minerals from the soil. Water  diffuses into the root hairs as the concentration of water is more as compared to  root hair.  But in case of minerals these move from lower concentration to molecules of  higher concentration. So the minerals from the soil along with water move into the  roots. So this is active transport in the opposite direction which needs energy.