The Arabic word for orphan is yatîm. Its linguistic meaning is simply "something that is singular and alone." When the word is used in the context of a human being, it means "a minor who has lost his or her father."

By God’s Divine wisdom, Prophet Muhammad (peace be upon him), in order to console the hearts of all orphans that would come after him, as he, the best of all mankind and the most beloved to God, was an orphan.Prophet Muhammad used to care for orphans and he used to ask his companions to protect them and to treat them well. He also showed the merits that come from that.
Al-Bukhari narrated that Prophet Muhammad, said: “I and the custodian of an orphan are like this (together) in Paradise”, and he joined his forefinger and middle finger together.”
Ibn Majah also narrated on the authority of Abu Huraira that Prophet Muhammad said: “The best Muslim house is a house in which an orphan is well treated; and the worst Muslim house is a house in which an orphan is badly treated.”
Abu Hurairah (RA) reported Allah’s Messenger (SAW) as saying, “He who strives to serve a widow and a poor person is like the one who strives in Allah’s way.” He also reported that when a man complained to the Messenger of Allah of being hardhearted he said, “Show affection to the orphans and feed the poor.”
“Would you like that your heart becomes soft and that you acquire what you need? Be merciful with the Orphans, pat his head and feed him from what you eat.” [At-Tabaraanee & As-Silsilah as-Saheehah]
Narrated Sahl bin Sa`d: The Prophet (ﷺ) said, “I and the person who looks after an orphan and provides for him, will be in Paradise like this,” putting his index and middle fingers together. [Sahih al-Bukhari 6005]
Abu Hurairah (RA) reports that the Messenger of Allah (SAW) stated”Whoever caresses the head of an orphan (in affection), solely for the sake of Allah, a good deed will be written to his account for every hair over which he passed his hand, and whoever treated an orphan (boy or girl) with goodness and kindness, he and I will be close to each-other in Heaven as these two fingers” The Prophet (SAW) made a gesture with his fingers as explained above.

The above Prophetic Hadiths show clearly that if someone takes good care of an orphan, he is sure to enter paradise by his good care.