There will be a screen on it and it has various reducing parts in it. Aerators reduce the water flow to 2.5 gallons per minute. If your sink drips , most likely washers are the culprits. Check Gadgets for more water savings. The kitchen sink gets a lot of use- from washing dishes to rinsing out paintbrushes.
Water quality is something to keep in mind as dirty water is going down the drain.
If you use a dishwasher, make sure to wash a full load, or use the appropriate cycle. If you hand wash dishes, use a bowl for sudsy water and one for rinse water. Turn off the water when it is not in use. An average American family can wash about 380 loads a year and can save over 5,700 gallons of clean, drinkable water each year with a front loading washing machine. Check each model's water consumption when shopping for a new washer.