Your birth family are the parents who gave birth to you, who you don't live with. Saying 'birth family' can stop people getting confused between them and the families who foster or adopt you.
We know it might be hard to leave your birth family, so your social worker will support you as much as they can. You might still be able to see them, unless it would be harmful to you. Your social worker can help with this.
The 'life story book' that you've worked on with your social worker will help you to remember your birth family when you don't live with them.
If you have brothers and sisters who've been adopted into different families, ask your social worker about staying in touch with them.