Cheaper tablets generally only work on wifi, rather than the 3G or 4G mobile phone networks. (Those that can connect to mobile phone networks tend to be far more expensive). So you need to be in range of a wifi signal to get internet access with them (but, of course, you can still play videos and music tracks, play games and do lots more, without internet access). With free wifi becoming increasingly available these days (e.g. in Wetherspoon's pubs, McDonald's, major railway stations, Costa, larger branches of Asda and Tesco, etc, etc) that's not much of a problem for many people.