It’s generally recommended that you drink 4-6 cups (around 32-64 ounces) of water daily.  Everyone is different, the amount of water recommended for you might be different for someone else, so that’s probably why you’re finding different amounts on different websites.  Losing water throughout the day- due to exercise or heat- will increase your overall intake needs. Your physician will have a better idea what your individual needs are, but 4-6 cups a day is a great place to start!