Siblings refer to either the brother(s) or sister(s) of a person. This relationship can be a biological relationship, i.e. a common parent, or it can be a relationship formed through the adoption of one child by a parent with existing biological children or other adopted children.
This is a common topic in parenting. When there are multiple children in a single household, parents often have to act as peer mediator or referee when an argument ensues between two or more siblings. Issues with siblings can stem from perceived parental preferences, acquisition of material objects (i.e. gifts), or age-related differences between siblings (i.e. regressive behavior of a toddler or pre-school age child after a new baby comes home).