For a new installation, the latest stable branch is usually your best choice. The last build information tells you when it was last updated with a bug fix or a patch. This is usually irrelevant to you; the version number determines which features you get, not the build time.
For a production server, do not use the standalone packages mentioned earlier. They are insecure, because they are meant for use by a Moodle developer for experimentation and development. To make the development of a site easier and faster, security settings that would slow down development have been turned off by default. Standalone packages are a good choice if you want to experiment or develop a Moodle site on your local (non-networked) computer. ...
