The most common method to purify water is to filter it. There are lots of filters with advantages and disadvantages
Pump Filters - Fairly fast but a bit bulky. In the US there is no need for pump filters that also provide a chemical treatment, so save your money.
Gravity Filters - These filters can be really convenient in camp. They can carry a lot of water, reducing the trips to the water. Can provide water for a group. They are slower so when you are on the trail they will slow you down.
Squeeze - These simple filters can be placed on a bag or bottle. These have become a really popular option. They can make refilling really fast since you can filter later. (I use a Sawyer Squeeze (Sawyer Mini) with bottles and a Gravity Bag, moving the Sawyer Mini wherever I need it.) The water bottle popularly used is the Smart Water Bottle but the Clear American sparkling water bottles at Walmart also work and are less expensive.
Great if you need boiled water for a meal. If you want cool water this is slow to heat and slow to cool. It also and uses fuel. For these reasons it usually is a backup method. The amount of time needed can vary based on altitude. The PCT Association just recommends bringing it to a boil. The NPS recommends boiling for one minute and 3 minutes if over 6500 feet.
Lightweight. Follow instructions giving time to work. Flavors the water. Sometimes used as a backup plan.
Fairly fast and lightweight. Has some failure risks with breaking and needs batteries. Needs clear water to work. I recommend a backup option (chemical.)
Do not let it freeze.
Backflush when necessary.
Disinfect when storing