Blended Family: This is a term that gets thrown around a lot in the media. Its basic definition is a family in which not everyone is biologically related – it’s a “blending” of biological parents, stepparents and their children.

Stepfamily: A family that’s made up of two adults and their children from previous relationships or marriages. In some cases just one of the adult partners has children to bring to the relationship; in others both partners have children.

Bonus Family: This is a term coined by the non-profit organization of the same name. It’s a different way of looking at stepfamilies – it’s seeing a stepfamily as a “bonus” family. The term was created because the word “stepfamily” has negative connotations for many people (think Cinderella and the wicked stepmother).

When stepfamilies form, it changes stuff for the kids involved. You might find yourself with a new title like “stepbrother” or “stepsister.” According to the Stepfamily Association of America, there’s a name for every member of the new family:

Sibling: Your siblings are your brothers or sisters. Siblings are biologically related and have the same two parents.

Stepsibling: A stepbrother and stepsister would be your stepsiblings. These are the children you’re related to through your parent’s marriage, not by blood.

Half-sibling: A half-sibling is related to you by blood, but only by one parent. You would have either a different father or a different mother from your step-sibling. If your mother had a child with your stepfather, he or she would be your half-sibling.

Mutual Child: If the adult partners in a stepfamily have a child, he or she is the “mutual child.” This term basically just distinguishes between which children are from previous marriages and which are from the current marriage. If your Mom and your stepdad have a child, he or she is a mutual child and your half-sibling!

Residential Stepchildren: These kids live with their parent and a stepparent for most of the year.

Nonresidential Stepchildren: Kids who just visit their stepfamily (a parent and a stepparent) and don’t live there full-time are “nonresidential.”