"易しい(yasashii)" and "簡単(kantan)" have almost same meaning "easy". ex) 易しい問題、簡単な問題　easy question But "簡単" also means "simple" , while "易しい" doesn't have such meaning. ex) 簡単に説明する。explain simply. (may be in a few words) . 易しく説明する。explain (may be in detail) in order to be easy to understand.