There are many and varied types of family in the UK.
Nuclear family - a family unit consisting of two adults and any number of children living together. The children might be biological, step or adopted.
Extended family - grandparents, aunts, uncles, and cousins, either all living nearby or within the same household, eg if a married couple lives with either the husband or wife's parents, the family changes from a nuclear to extended household.
Reconstituted family - also known as a 'step family'. A family where one or both adults have children from previous relationships living with them.
Single parent family - consists of a parent not living with a partner, who has most of the day-to-day responsibilities for raising the children. The children will live with this single parent for the majority of the time but may still have contact with their other parent.
Same-sex family - since civil partnerships were legalised in 2005, the number of same sex families has been growing (same-sex marriage was legalised in 2014). Same-sex couples cannot conceive together, so their children may be adopted or be the biological children of one member of the couple. They may also be from a sperm donor or a surrogate birth mother.