This video explains you the concept of Threaded binary tree.
Hope this will help you.
Also See:
Data Structure Introduction : https://youtu.be/1rzzwXNlAh0
Data Structure Stack : https://youtu.be/yaOunS3KGkA
Data Structure Circular Queue : https://youtu.be/8jy9MO9K6ME
Application of Stack : https://youtu.be/cafqRStpiMQ
Stack Implementation using Array : https://youtu.be/aTRyB03i6mQ
Queue Implementation using Array : https://youtu.be/r26D1oQO3mU
Conversion Infix to Prefix : https://youtu.be/US1rA6UZvAQ
Linear Queue : https://youtu.be/rEXJeFEgFGU