This short post is to counter the often made claim that a certain way of approaching meditation is the right way, whereas in practice there are lots of practices and many ways. It is not the case that there is a certain order, or certain path that we must follow. In fact, the Sutra of Perfect Enlightenment notes 39 ways to combine the different types of meditation and makes it clear it considers different paths suitable for different practitioners.
The two types of meditation found in the famous Buddhist eightfold path are concentration (samadhi) and mindfulness (sati) although there are more types such as super-mundane powers (abhijna), tranquillity (samatha), and insight (vipassana). And despite some schools emphasising one form of meditation over the others there is not one way to achieve enlightenment and the tradition has insisted that you can do it by first doing concentration or mindfulness.
The traditional Therividia view, found in the Visuddhimagga and elsewhere is that there are those who follow the ‘wet-method’ or ‘way of calm’ (samathayana), and in contrast there are those who work in ‘pure insight’ (visuddhimagga) which is called the dry method  . Buddhaghosa says these are the two roots one must master before turning to the purification of view engendered through insight practice  . And, as already stated the Mahayana is much more flexible and admits multiple ways and practices to reach the same goal.
WHAT ARE THE JHANA?
Jhana is the Pali word that describes a series of cultivated states of mind, which lead to a “state of perfect equanimity and awareness (upekkhii-sati-piirisuddhl). Further, it must be noted that the jhana’s have mindfulness factors.
PALI-CANNON’S TEACHINGS ON JHANA
The Pali-cannon says quite a lot about the Jhana’s such as noting that it is extremely difficult to obtain even the first Jhana and in the Upakkilesa Sutra there is a detailed account of the Buddha’s struggle to obtain the first absorption and the case is similar for others monks (eg, A.I.12).
CONCENTRATION AND THE FIRST JHANA
The first Jhana is not just a relaxed state of being or merely feeling happy but a deeper state of meditation where one does not hear any sounds and one cannot speak (cf, A.V.13). The experience of the first absorption is an otherworldly experience (cf, A.IV.430) constituting another world in the psychological and cosmological sense (cf, D.III.215 and S.V.56) and to reach here is to enter a ‘Superbly Extraordinary State’ (cf, M.I.159 and M.I.147). The absorption of the first Jhana is beyond mere reflection and conceptual thought. Concentration is essential for full awakening (cf, A.III. 426).
NOT ANY CONCENTRATION, BUT RIGHT CONCENTRATION.
Over and over again in the Pali-cannon right concentration (samma samadhi) is equated with the four absorptions (eg, D.II.313) however, as the Buddha’s former teachers show despite deep concentration/absorption one has not reached enlightenment without combining it with right view (cf, A.III.19; A.III.200; A.IV.99; A.IV.336; A.V.4-6 and A.V.314). It is worth noting that it is possible to enter a jhana and still have all the hindrances obsessing the mind (cf, Gopakamaggallana Sutra).
CONCENTRATION AND STREAM ENTRY
A sotāpanna (“stream-entrant”) is a person who has seen the Dharma and consequently has dropped the first three fetters that bind a being to rebirth. A Sotapanna will reach full enlightenment within the next seven lives. Perhaps the biggest difference between a sotapanna and Buddha is the lack of absorption. According to a discourse in the Itivuttaka the hindrances can be removed during walking meditation (a posture not suitable for attaining absorption – cf It.118) and listening to the Dharma (cf, S.V.95) and for people who have never meditated (D.I.110; D.I.148; M.I.380; A.IV.186; A.IV.213).
CONCENTRATION AND ONCE RETURNERS
Those people who have gained the ability to enter absorption at will are never going to return to this world (A.II.126) and the difference between a once returner and never returner is the development of concentration (cf, A.IV.380; A.I.232; A.I.233).
THE JHANA’S HAVE MINDFULNESS FACTORS
 Wunnita (1957), 7
 Turner (2009), 67
 Braun (2013),The Birth of Insight: Meditation, Modern Buddhism, and the Burmese Monk Ledi Sayadaw, University of Chicago Press