The improved Installer can be found under the Extensions Menu. With versions prior to Joomla! 1.5 you needed to select a specific Extension type when you wanted to install it and use the Installer associated with it, with Joomla! 1.5 you just select the Extension you want to upload, and click on install. The Installer will do all the hard work for you.

Mambots have been renamed as Plugins.

Mambots were introduced in Mambo and offered possibilities to add plug-in logic to your site mainly for the purpose of manipulating content. In Joomla! 1.5, Plugins will now have much broader capabilities than Mambots. Plugins are able to extend functionality at the framework layer as well.

The collation option determines the way ordering in the database is done. In languages that use special characters, for instance the German umlaut, the database collation determines the sorting order. If you don't know which collation you need, select the "utf8_general_ci" as most languages use this. The other collations listed are exceptions in regards to the general collation. If your language is not listed in the list of collations it most likely means that "utf8_general_ci is suitable.