Hi Raj and welcome to Dermatalk.
You are correct in that drinking 8 to 10 glasses of water per day is healthy for a person. But it really does't have to be plain water. Some people just can't stand to drink that much water per day so it can be flavoured and in the form of juices as well.
My problem with drinking that much water is that I just forget. I try to keep a litre at my desk so I remember to drink that during the day and always have a glass with my meals.