This report provides detailed evidence on media use, attitudes and understanding among children and young people aged 5-15 years, information about media access and use among children aged 3-4 and parents’ views about their children’s media use, and the ways that they monitor or limit children's use. Some children reported there was not enough content on both traditional television and YouTube that reflected their lives. TV was seen as an important source of news for children, and viewed as more likely than social media to report truthfully. Newer forms of online advertising were hard for children to identify. Some children reported negative experiences online and these were found to have increased from an earlier survey in 2016. Parents were not always aware of the minimum age requirements for the sites used by their children. Compared with parents’ responses in 2016, in this 2017 survey, more were concerned about their children’s media use, and more were taking action to protect their children online.