Silver lining

Hi, could you explain the meaning of "Silver lining", when and how to use this word?

It means that a negative situation has produced something that is very positive. The very positive thing or situation is the "silver lining".
For instance, many people agree that one of the "silver linings" of World War 2 was the increae in technology that hastened the development and start of the computer era.

I think this comes from thunder clouds, which are often very dark and threatening but which often may have a silver gleam of sunlight along one edge - the 'silver lining' to the cloud.