The basic meaning of meditation is awareness, consciousness, witnessing and seeing. Spiritual meditation should happen automatically.
Innumerable imaginations and thoughts go on in our mind simultaneously. Due to this, there is uproar in the mind and brain. We don't want to, yet it goes on. You are reducing and weakening yourself by thinking continuously. Meditation is removing unnecessary imagination and thoughts from the mind and going into pure and serene silence.Japa meditation is meditating with a mantra.
Note: Mantra Japa should be taken seriously as this involves immense energy. So a guru is needed in this process to have a proper effect.
Well, when we sit with our eyes closed, there is often a complaint that the thoughts of the whole world come at the same time. Things of the past or plans for the future, fantasies etc. all thoughts keep buzzing around the brain like flies.
How to get rid of this? It is believed that meditation cannot happen as long as there is thought. Now no one is even ready to believe that thoughtlessness can also happen. What's the harm in trying and seeing. Osho says that meditation is the death of thoughts. You just start meditating and know its major benefits.