Halal

Halal is an Arabic word means lawful. It refers to things or action permitted by Shariah law without punishment imposed on the doer. It is usually used to described somethingthat a Muslim is permitted to engage ini. i.e. eat, drink or use. The opposite halal is haram, which is Arabic word for unlawful or prohibited.

Sunnah in Arabic language means 'road' or 'practice'. In the language of the Prophet and the Companions it denotes the whole of licit (lawful) practices followed in the Religion (Ad-din), particularly the pristine (hanif), path of Prophet, whether pertaining of belief, religious and social practice or ethics genarally speaking.

References:
1. http://www.halal.gov.my/
2. http://www.sunnah.org/fiqh/usul/meaning-sunnah.htm