What is difference between boiling and vaporization ?

Differences are as under:

1. Scope of molecules : In boiling molecules of whole liquid go into vapor state. In vaporization only surface molecules go into vapor state

2. Energy required: Boiling requires external source to break molecular bonds. In vaporization heat gained from sorroundings is enough for surface molecules

3. Temperature: Boiling occurs only at boiling temperature. Vaporization occurs at all temperatures. 

4. Interface: Boiling has a solid-liquid interface whereas vaporization has a liquid-vapor interface.