Connected Chain of Transmission (اتصال السند):

A chain of transmission which is connected without interruption in such a manner that it is logically acceptable that the succeeding narrator received the hadith from the preceding one. Therefore, there should be no gap, whether in time or place, which may make their meeting impossible.

Disconnected Chain of Transmission (فقد اتصال السند):

A chain of transmission which is interrupted in such a manner that it is not logically proved that the succeeding narrator had received a hadith from the preceding one.

Descending Chain of Transmission (الإسناد النازل):

This is the opposite of the Ascending Chain of transmission as the number of narrators is more than that found in another chain of transmitters or in the other chains as a whole.

Ascending Chain of Transmission (الإسناد العالي):

This term refers to any hadith whose chain of transmission begins near the Messenger of Allah and the number of narrators is less than that found in another chain of the same hadith or in other chains as a whole.

Performance (الأداء):

This term applies to transmitting the hadith from whomever it was heard.

Way of Performance (صيغة أداء):
Certain formula through which the narrator transmits a hadith.

Narration of the Elders (رواية الأكابر):
The term refers to the transmission of a narrator from someone whom he exceeds whether in age or status or in both.