You should be able to identify the part of a plant that absorbs water (i.e. ROOTS).
Remember to water near the base of your plants to be as efficient as possible.
You should be able to water your plants using different methods or tools (i.e. watering can, sprinkler, soaker hose, drip tape, hose, etc.).
You should be able to determine when it is best to water your plants.
Check the soil around your plants! If it clumps in your hand, it likely already contains enough moisture and does not need to have any water added. If the soil does not clump in your hand, it is likely dry and should have water added.
Listen to your plants! If they look droopy, wilty, or dull, they could probably use a drink of water.