Why would someone want to convert columns into rows (ie pivoting)? Which problem does it solve?

I found some links, but did not get satisfactory answers to the questions.

http://codeghar.wordpress.com/2007/11/03/pivot-tables/

http://msdn.microsoft.com/en-us/library/ms177410%28SQL.105%29.aspx

Usually, it's because the layout works better in a report, or user interface after pivoting.

Data on a normalized database may result in data in the "shape" of multiple records, where the UI wants to see those records as fields. Data normalization is great, but when it comes to representing data in a concise, natural format, pivoting is often necessary.

example here.

Granted, the example I linked to is Excel, not a true DB, but the pictures describe an example of where the pivoted data looks more natural, and the concept is the same.