
Adoption is a process whereby a person assumes the parenting of another, usually a child, from that person's biological or legal parent or parents. Legal adoptions permanently transfer all rights and responsibilities, along with filiation, from the biological parents to the adoptive parents.

An AIDS orphan is a child who became an orphan because one or both parents died from AIDS.

Attachment in children is "a biological instinct in which proximity to an attachment figure is sought when the child senses or perceives threat or discomfort. Attachment behaviour anticipates a response by the attachment figure which will remove threat or discomfort". Attachment also describes the function of availability, which is the degree to which the authoritative figure is responsive to the child's needs and shares communication with them. Childhood attachment can define characteristics that will shape the child's sense of self, their forms of emotion-regulation, and how they carry out relationships with others. Attachment is found in all mammals to some degree, especially primates.

Attachment theory is a psychological, evolutionary and ethological theory concerning relationships between humans. The most important tenet is that young children need to develop a relationship with at least one primary caregiver for normal social and emotional development. The theory was formulated by psychiatrist and psychoanalyst John Bowlby.

A baby hatch or baby box is a place where people can bring babies, usually newborn, and abandon them anonymously in a safe place to be found and cared for. This kind of arrangement was common in the Middle Ages and in the 18th and 19th centuries, when the device was known as a foundling wheel. Foundling wheels were taken out of use in the late 19th century, but a modern form, the baby hatch, began to be introduced again from 1952 and since 2000 has come into use in many countries, notably in Germany, where there are around 100 hatches, Czech Republic (76), Poland (67), and in Pakistan where there are more than 300 as of 2006.

Thomas John Barnardo was an Irish-born philanthropist and founder and director of homes for poor and deprived children. From the foundation of the first Barnardo's home in 1867 to the date of Barnardo's death, nearly 60,000 children had been taken in.

Barnardo's is a British charity founded by Thomas John Barnardo in 1866, to care for vulnerable children. As of 2013, it raised and spent around £200 million each year running around 900 local services, aimed at helping these same groups. It is the UK's largest children's charity, in terms of charitable expenditure. Its headquarters are in Barkingside in the London Borough of Redbridge.

Beechholme was a children's home in Fir Tree Road, Banstead, Surrey. It was founded in 1879 as a Residential School for poor children from the slums of Kensington and Chelsea and run under a Village system.

Edward John Mostyn Bowlby, CBE, FRCP, FRCPsych was a British psychologist, psychiatrist, and psychoanalyst, notable for his interest in child development and for his pioneering work in attachment theory. A Review of General Psychology survey, published in 2002, ranked Bowlby as the 49th most cited psychologist of the 20th century.

Casa San Diego is a holding facility located in El Cajon, California for minors who are either unaccompanied at the United States border or who have been separated from their families. Currently, around 10 percent of children housed in Casa San Diego were separated from their parents on entry at the border. Casa San Diego currently houses boys and girls between the ages of 6 and 17.

The Dancing Water, the Singing Apple, and the Speaking Bird is a Sicilian fairy tale collected by Giuseppe Pitrè, and translated by Thomas Frederick Crane for his Italian Popular Tales. Joseph Jacobs included a reconstruction of the story in his European Folk and Fairy Tales. The original title is "Li Figghi di lu Cavuliciddaru", for which Crane gives a literal translation of "The Herb-gatherer's Daughters."

Deinstitutionalisation is the process of reforming child care systems and closing down orphanages and children's institutions, finding new placements for children currently resident and setting up replacement services to support vulnerable families in non-institutional ways. It became common place in many developed countries in the post war period. It has been taking place in Eastern Europe since the fall of communism and is now encouraged by the EU for new entrants. It is also starting to take hold in Africa and Asia although often at individual institutions rather than statewide. New systems generally cost less than those they replace as many more children are kept within their own family.
Fr. John Christopher Drumgoole was an Irish American Roman Catholic priest who was known for his work in caring for and educating orphaned and abandoned children in New York City, especially homeless newsboys. In 1883, he founded Mount Loretto, an orphanage and vocational school for boys in a then-rural section of Staten Island which later grew into a large complex that housed and educated thousands of boys and girls in more than a century of existence. As of 2015, the organization that Drumgoole founded continued to run programs that benefit needy children on a portion of the Mount Loretto property.

The Hôpital des Enfants-Trouvés was an institution of Paris established to take care of abandoned children.

Foster care is a system in which a minor has been placed into a ward, group home, or private home of a state-certified caregiver, referred to as a "foster parent" or with a family member approved by the state. The placement of the child is normally arranged through the government or a social service agency. The institution, group home or foster parent is compensated for expenses unless with a family member. In some states, relative or "Kinship" caregivers of children who are wards of the state, are provided with a financial stipend.

Kinder der Landstrasse was a project of the Swiss foundation Pro Juventute, active from 1926 to 1973. The focus of the project was the assimilation of the itinerant Yenish people in Switzerland by forcibly removing children from their parents, placing them in orphanages or foster homes. A total of about 590 children were affected by the program.

The Lady of the Wheel is a 2012 historical fiction novel by Sicilian American author Angelo F. Coniglio. The book follows the life of a girl who was abandoned as an infant, with the major themes of the book including poverty, exploitation and family values. Coniglio's work has been compared to the verismo (realism) of Sicilian author Giovanni Verga.
The left-behind children in China, also called "stay-at-home children", are children who remain in rural regions of China while their parents leave to work in urban areas. In many cases, these children are taken care of by their extended families, usually by grandparents or family friends, who remain in the rural regions.

The adoption of children by lesbian, gay, bisexual, transgender (LGBT+) people may be in the form of a joint adoption by a same-sex couple, adoption by one partner of the other's biological child, or adoption by a single LGBT+ person. Joint adoption by same-sex couples is legal in twenty-seven countries as well as several subnational jurisdictions and dependent territories. Furthermore, some form of step-child adoption is legal for same-sex couples in five additional countries.

Notable orphans and foundlings include world leaders, celebrated writers, entertainment greats, figures in science and business, as well as innumerable fictional characters in literature and comics. While the exact definition of orphan and foundlings varies, one legal definition is a child bereft through "death or disappearance of, abandonment or desertion by, or separation or loss from, both parents". According to the United Nations, the definition of an orphan is anyone that loses one parent, either through death or abandonment.

Maternal deprivation is a scientific term summarising the early work of psychiatrist and psychoanalyst John Bowlby on the effects of separating infants and young children from their mother although the effect of loss of the mother on the developing child had been considered earlier by Freud and other theorists. Bowlby's work on delinquent and affectionless children and the effects of hospital and institutional care led to his being commissioned to write the World Health Organization's report on the mental health of homeless children in post-war Europe whilst he was head of the Department for Children and Parents at the Tavistock Clinic in London after World War II. The result was the monograph Maternal Care and Mental Health published in 1951, which sets out the maternal deprivation hypothesis.

Mother's Choice is a local charity serving children without families and pregnant teenagers in Hong Kong. Mother's Choice was founded in 1987 by a small group of people concerned with the plight of Hong Kong's single teenagers and their family members coping with crisis pregnancy. Today, Mother's Choice works toward a stated goal of building stronger families.

An orphan is a child whose parents have died, are unknown, or have permanently abandoned them.

Reactive attachment disorder (RAD) is described in clinical literature as a severe and relatively uncommon disorder that can affect children. RAD is characterized by markedly disturbed and developmentally inappropriate ways of relating socially in most contexts. It can take the form of a persistent failure to initiate or respond to most social interactions in a developmentally appropriate way—known as the "inhibited form". In the DSM-5, the "disinhibited form" is considered a separate diagnosis named "disinhibited attachment disorder".

Sabrina Bicknell, better known as Sabrina Sidney, was a British woman abandoned at the Foundling Hospital in London as a baby, and taken in at the age of 12 by author Thomas Day, who tried to mould her into his perfect wife. She grew up to marry one of Day's friends, instead, and eventually became a school manager.

The Stolen Generations were the children of Australian Aboriginal and Torres Strait Islander descent who were removed from their families by the Australian federal and state government agencies and church missions, under acts of their respective parliaments. The removals of those referred to as "half-caste" children were conducted in the period between approximately 1905 and 1967, although in some places mixed-race children were still being taken into the 1970s.

Street children are poor or homeless children who live on the streets of a city, town, or village. Homeless youth are often called street kids or street child; the definition of street children is contested, but many practitioners and policymakers use UNICEF's concept of boys and girls, aged under 18 years, for whom "the street" has become home and/or their source of livelihood, and who are inadequately protected or supervised. Street girls are sometimes called gamines, a term that is also used for Colombian street children of either sex.

The Thai Children's Trust, formerly Pattaya Orphanage Trust, is a registered charitable organization in the United Kingdom which supports vulnerable and disadvantaged children in Thailand. It helps fund projects for orphans, refugee children, HIV positive children and children with AIDS, homeless children, tsunami orphans and children and young people with disabilities. The Trust has recently helped support the Teacher Preparation Center, a training school for mobile teacher trainers, in Mae Sot. The TPC trains trainers who work in the Eastern states of Burma/Myanmar, trying to restore and improve educational standards in areas ravaged by years of civil war. The Trust has also found some funding for villageONE, a project combining education and community development which hopes to start work in Mon State, Burma/Myanmar, later this year.

Ursula is the colloquial name for the Central Processing Center, the largest U.S. Customs and Border Protection detention center for undocumented immigrants. The facility is a retrofitted warehouse that can hold more than 1,000 people. It was opened in 2014 on W. Ursula Avenue in McAllen, Texas. In June 2018, it gained notoriety for the practice of keeping children in large cages made of chain-link fencing.

A waif is a living creature removed, by hardship, loss or other helpless circumstance, from its original surroundings. The most common usage of the word is to designate a homeless, forsaken or orphaned child, or someone whose appearance is evocative of the same.