甜头 literally means 'sweet taste' (甜 'sweet' + 头 'head/tip'), but it is far more commonly used as a figurative noun meaning 'benefit' or 'advantage'—especially a small one given to entice someone into doing something. You will hear it in contexts like 尝到甜头 ('to taste the benefit / get a first positive result') and 给点甜头 ('to give someone a little inducement'). The literal meaning exists but is rare in everyday conversation.