You borrow something from somebody, but lend something to somebody.
When you borrow, you are the receiver, for example
I did not have any money, so I had to borrow $50 from my brother.
When you lend, you are the giver and someone else is the receiver, for example
My brother did not have any money, so I lent him $50.
Another example, combining the two:
I borrowed a book from the library and then I lent it to my friend for a day.
Hope it hepls,