BelieveToSee, meditation serves many purposes. There are so very many types of meditation.
One is mindfulness meditation. It is one of the most common types recommended for a lot of people to start. Some say it is mindfulness of passing thoughts, while others say they work to just let thoughts pass and remain mindful of their bodies, or breath, or whatever. It has nothing to do with religion or spiritual beliefs unless someone wants to implement that into their process.
Some types of meditation are meant to train the mind to clear. These can be closely related to mindfulness, as it is not a struggle to stop thought, but a means of allowing thoughts to pass until your mind calms.
There are also types of meditation built around intense focus, such as a mantra (repeated phrase -- sometimes phrases in a specific language (like Om Mani Padme Hum); or a thought to embed into the subconscious; or possibly clearing the mind and focusing on the flame of a candle and rejecting all outside influences.
Some people meditate to focus on internal 'energies,' and learning how to control and manipulate them.
There are so many types and purposes for meditation.