This is the 11th most frequent Korean word.
통해
"Through" or "via."
In this sentence, '통해' is used in the format '통해서,' indicating the medium or method (a friend) through which learning about the hobby occurred.
나는 친구를 통해서 새로운 취미를 알게 되었어.
I learned about a new hobby through my friend.
Here, '통해' sets out the medium (internet) by which the problem was solved.
인터넷을 통해 문제를 해결할 수 있었어요.
I was able to solve the problem through the internet.
In this example, '통해' designates the channel (program) through which assistance is provided.