Antibiotics are drugs that kill bacteria that can cause certain infections, including strep throat. Antibiotics don't help infections caused by viruses.
Like other drugs, antibiotics can have side effects. Using antibiotics when they are not needed may put your child at risk of harmful side effects with no benefit. Also, when antibiotics are used when they are not needed, bacteria become resistant to treatment, which means that the antibiotics are no longer effective. That's why it's so important for doctors to make sure antibiotics are needed before they prescribe them.