Crom Thanks a lot for your kind replies, I was just little confused. I asked this question to a teacher today and he said "At the end of (something) and In the end (by itself)". I couldn't check this, but I think is not completely wrong accoriding to the text I was reading.

At the end of the book, I realised there was a typo.

In the end, I realised there was a typo in the book.

What d'you say?

Your sense of using "at the end" and "in the end" is correct;however , to me, the verb "realised" doesn't seem to fit with "at the end".

At the end of the book, I found there was a typo. -- May be at the last page of the book, you found a typo.

In the end, I realized there was a typo in the book -- After reading the book/finally, you realized there was a typo in the book.

At the end of the book, I found there was a typo. -- May be at the last page of the book, you found a typo.

In the end, I realized there was a typo in the book -- After reading the book/finally, you realized there was a typo in the book.

rishonly