Home water filters have the benefit of cost savings over bottled water. Most bottled water which is regulated by the Food and Drug 
Administration only when it goes across state lines. Bottled water may contain as the same impurities as the tap water delivered through you water pipes as the FDA only requires the water be packaged under strict sanitary conditions.
Water filters remove impurities thus improve the taste of your tap water. There are various types of filters available. Most filters work the same way. The water passes through the device that removes the toxins and impurities. The easiest and simple solutions are the pitcher and faucet types. The biggest disadvantage of these type of filters is the cost of replacement cartridges every few months. You will need to decide which type of filter best suits your personal needs.
Pitcher filters are the easiest way to filter your water, however, it is not the fastest way. It can take up to fifteen minutes to filter half a gallon of water.
Faucet mounted filters typically have a lever that you select between unfiltered and filtered water. They are easy to install and cost about the same as the pitcher styles. Cartridges will need changed between one and three months based on your usage.
Under sink styles have the advantage of being out of sight and the cartridges being larger do not need to be changed as often. They will need to be professionally installed unless you are a fairly skilled do it yourselfer.
Whole house filters are just that. They are connected to the incoming water supply and filter all the water that is used. They are not expensive but do require professional installation. The filters last about six months.
All of the systems discussed above are meant for use with safe, treated drinking water. If you use well water, you may need a different kind of system. Contact your local agricultural extension office for guidance.