When your parents live together, they are both responsible for taking care of you. When your parents stop living together, this might change.
For example:
Your parents might be able to agree on custody and access themselves. But if they can't agree, even with the help of a mediator, they can go to court and have a judge decide.
If this happens, the judge who is making the decisions will consider things like:
This is called the “best interests of the child test”.
If one parent has custody, the other parent usually has access, which means that you visit them. There are lots of different ways to arrange how you spend time with the parent who has access. Visits might be for a few hours every week, or for weekends or a few days every two weeks or month. If the parent with access lives far away, access can also include keeping in touch in other ways, like phone calls, e-mails, and letters.
Access arrangements may be very specific — actually spelling out the specific hours and days for visits — or very general and flexible.