There are many hydration options; a water bottle, hydration bag, hydration pack, collapsible bottle, even a canteen (but lets leave those antique aluminum things at home!).

For a casual hike, a water bottle keeps things simple.

If the hike goes on for more than a couple hours, study your water system .

   There are hip belts that carry 1, 2, or 3 bottles. If your hike is strenuous, consider a hydration pack. Water is carried inside the backpack in a collapsible reservoir with a hose to the front. Drink your water using a simple-hands-free-suction valve. When planning an extended backpacking trip, make sure that you have the capacity to carry at least four liters of water.  Many of the newer backpacks and daypacks are "hydration compatible."

Most of the daypacks are designed to carry a 1-liter reservoir; most backpacks will accept a two or three liter reservoir. Backpackers should consider some type of collapsible "bucket" for hauling water to a campsite. Most can be used as a field shower too.