Google is a company with a mission of Documenting and sharing Knowledge. Google uses automated scripts called robots or crawlers to "crawl" through the websites and document where to find what. Google shares this Knowledge through it's search engines and news aggregator. The advertisements on Google's search engines are it's main source of income.
Google mail (Gmail) is the second initiative taken by google, first one being the web & image search initiative. Gmail became a gateway to other Google services through using same account login.
Google's major FOSS initiative is Android, an open source mobile operating system.
Chrome OS is another FOSS initiative taken by Google, and is catching up fast in the developed world.
Google Maps is a Free web map service that powers many map-based services, including the Google Maps website, Google Ride Finder, Google Transit, and maps embedded on third-party websites via the Google Maps API.