The easy answer to this question is, because every family is different. No two families are identical; even two separate one-parent families will have their own routines, lives, and ways of living.
The main types of families are;
Two-parent families (that could be a mum and dad, two mums, or two dads). A lot of people want to have children, and when two people in a relationship decide to become parents, there’s a lot of different ways; by a baby growing in a woman’s womb, though a process called IVF, by fostering, or via adoption.
One-parent families most often happen when a relationship between two parents ends. The parents will then split up and the children will live with one of them. That’s not always the case; single people will sometimes adopt by themselves. I did that, and it was the best decision I ever made.
Split families. This is where the two adults in the family have split up, but the children live between each parent’s house.
Step-families happen when the parents have a new partner, who might have their own children and often all live in the same house.
Maybe another question to ask is; what is the most important thing in a family? Is it love? Generosity? Kindness? Loyalty? Maybe all of those and a hundred other things that matter to each family. The main thing about families is that they love and support each other, no matter what they look like.