For women, the fallopian tubes that carry eggs to the uterus are tied. For men it's a vasectomy, where the tubes that carry the sperm to the testicles (balls) are cut and tied. This is done under local anaesthetic and is IRREVERSIBLE, it cannot be undone.

It works as the egg and sperm cannot reach other, so pregnancy is permanently prevented.

This is sterilisation and is available only if you're over 18. You have to think carefully about this as it's forever. It's not recommended for young people because you may change your mind later and want children. It is recommended if you do not want any more children or have reached a decision to never have children.