Word: Sanad

Meaning: Chain of oral transmission   

Word: Hadith

Meaning: A report concerning the saying or action of the Prophet that has been orally transmitted to later generations.

Word: Sunnah

Meaning: Sunnah are the sayings and actions of the Prophet   

Word: Chain of oral transmission

Meaning: Relating a word or sentence to another person by word of mouth, and then that person relating it to someone else.