The "Gallery" component is a minimalistic and completely file-based gallery for Joomla 2.5 and Joomla 3. File-based means that there is no need for a database and you could manage all your photos in just one place: the file system. When you are creating a gallery, just upload your photos to the gallery folder and the whole gallery is automatically created.
The "Gallery" is the indirect successor of the Photoblog component, which is still available for Joomla 1.5.
The Photoblog component is a gallery software written for Joomla! 1.5. The component was originally designed as Photoblog. Meanwhile it includes also some elements of a full gallery component.
A demo of the Photoblog component is available at http://www.erdikon.de/fotos and the project page at https://webguerilla.net/projects-unmaintained/photoblog .