Meditation is a practice where an individual operates or trains the mind or induces a mode of consciousness, either to realize some benefit or for the mind to simply acknowledge its content without becoming identified with that content, or as an end in itself.
Meditation Includes Following:-
Preksha Meditation:-
Preksha meditation is the practice of purifying the emotions and conscious (chitta) and realizing the own self. If we talk about religion then i must mention that is part of Jain philosophy while it is very hard to differentiate jainism from hinduism. still both looks like similar and following same ritual as we know that It become a religion at same time when Budhism was establishing the root in India.
Vipassana Meditation:-
Vipassanā (Pāli) or vipaśyanā (Sanskrit: विपश्यन) in the Buddhist tradition means insight into the true nature of reality. In the Theravada tradition, this specifically refers to insight into the Three marks of existence: impermanence, suffering or unsatisfactoriness, and the realization of non-self. Vipasana is part of Budhism and we consider Budha as encarnation of Lord Vishnu in Kaliyug.
Traditional Meditation:-
In pre-modern and traditional Hindu religions, Yoga and Dhyana are done to realize union of one’s eternal self or soul, one’s ātman. In some Hindu traditions, such as Advaita Vedanta this is equated with the omnipresent and non-dual Brahman. In others, such as the dualistic the Yoga school and Samkhya, the Self is referred to as Purusha, a pure consciousness which is separate from matter. Depending on the tradition, this liberative event is referred to as moksha, vimukti or kaivalya.
Meditation According to Gherand Sahimta:-
1. Sthul Dhyana :- To focus on physical perception like Guru, any God etc. which ever you like the most and dettach from everything with attached with superior
2. Jyoti Dhyana:- Focus of Serpent power at Muladhar chakra.
3. Sukhsm Dhyana:- focus at eybrow center and stay in Shambhavi mudra.
Meditation according to Bhakti Sagar:-
1.Padast :- Focus as physically of your Guru or your God and retention of breath and finally start om chanting.
2. Pindast:- follow the meditation according to Chakra like Muladhar,swadhisthan,manipurak,anhad,vishudhi, ajana and barhamrandhra
3. Roopast:- start meditaion at eybrow center and get higher stages.
4. Roopatit:- Focus to existance of everywhere in micro and causal stages. After it nothing left in universe to know.
Meditation according to Shiva sahimta:- Lord shiva told meditaion according to chakra in Shushmana nadi.
Meditation according to Yog Vashisht :- To be observant and differentiate between Maya(Illusion) and Atman (soul). You may say Yog vashist follow the Shankya darshan which is similar as Janna Yog in Shrimad Bhagwad Geeta.