This is the 18th most frequent Tamil word.
இத
"It" (referring to something neutral or close).
'இத' in this sentence refers to an abstract concept or object which provides support.
இத ஒரு குழந்தைக்கு உறுதுணையாக இருக்கும்.
This will support a child.
'இத' here serves as a determiner pointing to the subject that teaches information.
இத உண்மையான தகவலை கற்பிக்கிறது.
This teaches the true information.
'இத' is used in this context to refer to something beneficial specific to the house.