Mi chiamo Antonio. My name is Antonio /Mi chiamo/ is a verbal voice from the reflexive verb /chiamarsi/, which, in turn comes from the non-reflexive and transitive verb /chiamare/ (meaning: to call) . In questions: Come ti chiami ? What is your name ? To say /I am Giovanni/, we could also say, /io sono Giovanni/.

it means "my name is.." or "I am.."