The Google main page is the page that is displayed when you navigate to the Google homepage: http://www.google.com/. The main page looks deceptively simple on the first glance, but there are plenty of features. Let's go through these features:
Web, Images, Videos, Maps, News, and more tabs
Web, Images, Videos, Maps, News, and more tabs

These links allows you to search Web pages, images, videos, maps, news stories, message groups, etc, or provide access to many other Google's services. Each of the search area share the same basic search functionality but may provide different search operators used for very specific queries.
iGoogle, Search settings, Sign in

Search query field
This is the textbox that you usually use to enter your search term(s).
Google Search button
Clicking this button or pressing the Enter key will submit your search query to Google.
I'm Feeling Lucky button
Clicking this button will take you directly to the page that is ranked the highest based on your search results.
Advanced Search
The Advanced Search page provides a simple interface for specific queries. Note that not all advanced operators are accessible here.

Allows you to search and translate across various languages.
Advertising Programs, Business Solutions, About Google
These links are more for advertisers, investors, webmasters, etc.
