SPLASH!!! Screen

Splash screen is a term used to describe an image that appears while a computer program is loading. Splash screens often don't cover the entire screen, but only a rectangle near the center. The splash screens of operating systems and some applications that expect to be run full-screen usually cover the entire screen.

Splash screens are typically used by especially large applications to notify the user that the program is in the process of loading. In other words, they provide feedback that a sometimes lengthy process is under way. A splash screen disappears when the application's main window appears.

Splash screens typically serve to enhance the look and feel of an application or web site, and hence are often visually appealing, and may also have animations, graphics and sound. However, since they may sometimes take a long time to load, they are not universally liked by users. Web splash screens are especially inconvenient for users with slow internet connections, as the first page takes longer to load.

When it comes to the Internet world(browser based application), then the Splash pages are the pages that the user sees before they actually get to a website; typically, they're flash and offer some kind of introductory animation. The user clicks "Skip Intro" or "Enter Site" and from there is taken to the site. Splash pages can also exist between pages on the same site.

You can find many good collection of Splash Screenshots at these websites:
VirtualPlastic.Net
GuideBookGallery.org