Picasa is a discontinued, cross-platform image organizer and image viewer for
organizing and editing digital photos, integrated with a now defunct
photo-sharing website, originally created by a company named Lifescape

Here is what the above code is Doing:
1. It’s defining a function called ‘describe_picasa’.
2. The function takes one argument, ‘organizer’.
3. It prints out a description of Picasa, using the ‘organizer’ argument.