How technology helps three girls stay in touch with Dad
26 March 2014 Last updated at 06:23 GMT
People in the military often move around for their job and can get sent away for months at a time to fight in war zones abroad.
For families left behind it can be a worrying time but modern technology helps to stay in touch.
We've been to see three girls whose dad is away in Afghanistan with the Royal Air Force to find out what life is like for them.
Watch Frontline Families on the Special's page of the Newsround website.