Anyone know a good meditation concentration? YouTube is full of them

Meditation is either relaxation while sitting or lying with eyes closed thinking nothing and breathing normally or to focus the mind for spiritual purposes. How long one should do such thing. For relaxation normally 10 to 15 minutes are enough unless one is very much exhausted when more time is required. For spiritual purposes there is no time limit ; the sages in India go meditating for days, months and years together .Fantastic ! One should not practice such thing while in home for a long time. Concentration is to focus all attention or in other words mental efforts. To centralize at one point is the prima facie requirement . If a book is read , concentration is essential .In fact in every field of life if concentration is missing the work is aborted.Training of mind should be taught to the wards from the childhood at homes, schools and the practice will make them perfect in the long run. However an adult with some effort will be able to concentrate the mind easily. For practicing meditation he/she will have to be extra vigilant because the mind has the habit to fly away too often and causes all the trouble due to its absence. So be patient and try and try again. Amen.