Before there Google+ and Google Photos, Picasa from Google was a good service to share and manage photos. You may not know, but it continued to exist all the time. Of course, during this time there have been no improvements and now Google announced the closure of its service.
This is logical, given that Google has launched a more convenient service for pictures and continue to improve it. The good news is that all the pictures that users add in Picasa, please have available in Google Photos. These two products using the same image database.
If users do not use Although Google Photos, they can still download all of Picasa Web Albums and view the associated tags, comments and subtitles.
They just will not be able to add new albums or systematize existing. Web Albums will continue to operate as usual until May 1, 2016, so that users have time.
And before that, Google has stop supporting Picasa March 1, 2016, the desktop application. Of course, it will continue to work in the future, but Google will not be further developed.