What constitutes kidnapping?

My friend Sam is divorced and has a son named "Ben" . Sam used to belong to the same church as Joe Doakes . Sam doesn't like Joe Doakes . At one point, Joe Doakes found Ben booking around town alone, and he picked him up . My guess is that Joe Doakes gave Ben a ride home, but I don't know for sure . Sam claims that Joe Doakes didn't have his permission to give Ben a ride . He also believes that Joe Doakes didn't have Ben's mother's permission either . This makes Joe Doakes a kidnapper in his estimation . I've asked Sam "What if somebody you like did the same thing ?" . I don't have a driver's license, so I'm not a likely example . We all live in a relatively large town, and kids "get around" . I believe Joe Doakes was only trying to be nice . Does Joe Doakes need Ben's parents' permission to give him a ride ? How is kidnapping defined ? What's the difference between kidnapping and giving a child a ride ? Thank you in advance for your answers .