In Raja Yoga which is a branch of the yoga system, the students training in this system are told to keep their concentration on the Trikute which is the seat of the mind.
Here, it is believed that the seat of the mind lies in the space between the two eyes or is said to be in the space at the top of the head.
Other schools of yoga recommend that one can concentrate on other parts of the body like the tip of the nose, on the navel chakra or even the base or Muladhara chakra which lies at the base of the spinal cord.
Now, how do you go about beginning your practice on concentration? Well you could start by getting your self seated comfortably on the floor with your legs crossed.
Though this is a highly recommended position it is not necessary that you should take up this position.
Just make sure that you sit in apposition which makes you feel comfortable and then you look straight at an object which is kept inline with your eyes.
Look hard for a couple of minutes and then gently close your eyes.
Next visualize the object and you will see the object clearly in the space between your eyebrows.
The image of the object slowly fades away after a short time.
The moment you feel it fading away open your eyes and look at the object again.
In the beginning you will find that it is quite difficult for you to retain the image of the object in your mind's eye for long but with continuous practice you will succeed.
You will find that you have lots of distractions like other pictures coming in between or you hear sounds which tend to distract your concentration.
You will soon realize that instead of the image of the object you have other thoughts bothering you.
But all these unwanted memories and thoughts will soon go away if you can keep your mind focused on the image of the object constantly.
Make sure that every time you get distracted you bring back your mind to the picture of the object.
Soon you will find that these unwanted thoughts do not bother you at all.
For the Hindus, meditation is a means to achieve the super conscious state called Samadhi.
This is the highest state which every Hindu who practices yoga strives to achieve.
In this state the self or the thought of conscious does not exist and gets merged with the Absolute or Brahman.
It is only with the guidance of the Guru that one can attempt to reach this highest state as the repercussions are many if the practice goes wrong leading one to become even mentally unstable or start hallucinating.
The Westerners however have a different goal to achieve when it comes to meditation.
They want to practice meditation for harnessing their dispersed thoughts so that a sense of discipline can be achieved.
They want greater focus or concentration so that they can deal with their everyday problems with clarity of thoughts.
With intense practice, concentration now becomes effortless where you will find that you can easily visualize and retain the image of the object for a longer period of time without distractions.
This is meditation.