In Buddhism, a sotāpanna (Pali), śrotāpanna (Sanskrit; Chinese: 入流; pinyin: rùliú, Tibetan: རྒྱུན་ཞུགས་, Wylie: rgyun zhugs), "stream-winner", or "stream-entrant" is a person who has seen the Dharma and consequently, has dropped the first three fetters (saŋyojana) that bind a being to rebirth, namely self-view (sakkāya-ditthi), clinging to rites and rituals (sīlabbata-parāmāsa), and skeptical indecision (Vicikitsa).
The word sotāpanna literally means "one who entered (āpanna) the stream (sota)", after a metaphor which calls the noble eightfold path a stream which leads to nibbāna. Entering the stream (sotāpatti) is the first of the four stages of enlightenment.
The first moment of the attainment is termed the path of stream-entry (sotāpatti-magga), which cuts through the first three fetters. The person who experiences it is called a stream-winner (sotāpanna).
The sotāpanna is said to attain an intuitive grasp of the dharma, this wisdom being called right view (sammā diṭṭhi) and has unshakable confidence in the Buddha, Dharma, and Sangha. The Buddha, Dharma, and Sangha, sometimes taken to be the triple refuge, are at other times listed as being objects of recollection. In general though, confirmed confidence in the Buddha', Dharma and Sangha, respectively, is considered to be one of the four limbs of stream-winning (sotāpannassa angāni). The sotapanna is said to have "opened the eye of the Dhamma" (dhammacakka), because they have realized that whatever arises will cease (impermanence). Their conviction in the true dharma would be unshakable.
They have had their first glimpse of the unconditioned element, the asankhata, in which they see the goal, in the moment of the fruition of their path (magga-phala). Whereas the stream-entrant has seen nibbāna and, thus has verified confidence in it, the arahant can drink fully of its waters, so to speak, to use a simile from the Kosambi Sutta (SN 12.68) — of a "well", encountered along a desert road.  The sotapanna "may state this about himself: 'Hell is ended; animal wombs are ended; the state of the hungry shades is ended; states of deprivation, destitution, the bad bourns are ended! I am a stream-winner, steadfast, never again destined for states of woe, headed for self-awakening!'".
However, the remaining three paths, namely: once-return (sakadāgāmin), non-return (anāgāmin), and sainthood (arahatta) become 'destined' (sammatta niyāma) for the stream-entrant. Their enlightenment as a disciple (ariya-sāvaka) becomes inevitable within seven lives transmigrating among gods and humans; if they are diligent (appamatta, appamāda) in the practice of the Teacher's (satthāra) message, they may fully awaken within their present life. They have very little future suffering to undergo.
The early Buddhist texts (e.g. the Ratana Sutta) say that a stream-entrant will no longer be born in the animal womb, or hell realms; nor as a hungry ghost. The pathways to unfortunate rebirth destinations (duggati) have been closed to them.
…those monks who have abandoned the three fetters, are all stream-winners, steadfast, never again destined for states of woe, headed for self-awakening. This is how the Dharma well-proclaimed by me is clear, open, evident, stripped of rags.
According to the Pali Commentary, six types of defilement would be eventually abandoned by a sotāpanna, and no major transgressions:
A sotāpanna will be safe from falling into the states of misery (they will not be born as an animal, ghost, or hell being). Their lust, hatred and delusion will not be strong enough to cause rebirth in the lower realms. A sotāpanna will have to be reborn at most only seven more times in the human or heavenly worlds before attaining nibbāna. It is not necessary for a sotāpanna to be reborn seven more times before attaining nibbāna, as an ardent practitioner may progress to the higher stages in the same life in which he/she reaches the Sotāpanna level by making an aspiration and persistent effort to reach the final goal of nibbāna.
According to Buddha, there are three types of sotapannas classifiable according to their possible rebirths:
The Buddha spoke favorably about the sotapanna on many occasions, and even though it is (only) the first of ariya sangha members, he or she is welcomed by all other sangha-members for he or she practices for the benefit and welfare of many. In the literature, the arya sangha is described as "the four" when taken as pairs, and as "the eight" when taken as individual types. This refers to the four supra-mundane fruits (attainments: "phala") and the corresponding four supra-mundane paths (of those practicing to attain those fruits: "magga").
The Sangha of the Blessed One's disciples who have practiced well... who have practiced straight-forwardly... who have practiced methodically... who have practiced masterfully — in other words, the four types [of noble disciples] when taken as pairs, the eight when taken as individual types — they are the Sangha of the Blessed One's disciples: worthy of gifts, worthy of hospitality, worthy of offerings, worthy of respect, the incomparable field of merit for the world.
This is called "the recollection of the Sangha" (sanghanussati). It can also be interpreted as, "They are the Blessed One's disciples, who have practiced well, who have practiced directly, who have practiced insight-fully, those who practice with integrity (to share what they have learned with others). They give occasion for incomparable goodness to arise in the world because gifts to them bear great fruit and benefit to the giver. The fifty-fifth Samyutta of the Samyutta Nikaya is called the Sotāpatti-saṃyutta, and concerns sotapannas and their attainment. In the discourse-numbers (of that chapter) 1-4, 6-9, 11-14, 16-20, 22-36, 39-49, 51, 53, 54, sotapannas are praised as Sangha members by and to: the sick, lay followers, people on their deathbed, bhikkhunis, bhikkhus, and devas, and end up becoming the well-being and benefit of many.
A Shrotaapanna is a first stage Arhat. Certification to the first fruit of Arhatship, which is within the Small Vehicle, comes when the eighty-eight categories of view delusions are smashed." p. 77 
The first fruit is that of Śrotāpanna, a Sanskrit word which means "One Who Has Entered the Flow." He opposes the flow of common people's six dusts and enters the flow of the sage's dharma-nature. Entering the flow means entering the state of the accomplished sage of the Small Vehicle.