Google (Global Organization of Oriented Group Language of Earth) is an American company that is most commonly famous as a search engine. It is used to find variety of information such as websites, pictures, maps, or answer of any question which you can think of.
To answer your questions - Google uses a computer program called a 'web crawler' that looks at the billions of websites available on the World Wide Web and reads their content to find searched "keywords" then it indexes these to make the website easier for a search engine to find.
Apart from search engine it offers services designed for work and productivity like Google Docs, Google Sheets and Slides, Email, Cloud Storage, Social Networking, Instant Messaging and Video Chat, Language Translation, Mapping and Navigation and much more.
Google was started in January 1996 by Larry Page and Sergey Brin as a research project for their PhD assignment. Initially, it ranked results by counting how many times the search term appeared on the page and later they found a way to analyze the relationship among websites and this technology was called Page Rank.
Google was initially called "BackRub" and eventually they changed the name to Google. In 2000, Google started selling advertisements associated with search keywords on page. Initially, ads were just text based and later turned into images and gifs. It is headquartered in California.
Currently, Mr. Sundar Pichai is the CEO of the company.
a) Android - Operating system for smartphones
b) Blogger - View and create a personal blog
c) Chromeback - Laptop using the google chromeOS
d) G Suite - A suite of cloud software for business
e) Gmail - Free online email servicing
f) Google+ - Social Networking site
g) Google Ads - It enables users to pay to advertise on the google search engine
h) Google Ad Sense - A service which pays website publishers are blog developers to show ads on their site.
i) Google Allo - Virtual Assistant etc.
j) Google Earth - Is a software program which allows a person to view almost everywhere on earth, can get directions or find places of interest and much more.
a) Advertising - Google generates most of its revenue from advertising. This includes sale of Apps, in-app-purchase, digital content products on Google and YouTube.
b) Search Engine - Google is most dominant search engine.
c) Enterprise Services - G-Suite is a monthly subscription to get access of many Google offerings for businesses and organization purpose.
d) Consumer Services - Like Web based services, Hardware and Software.
e) Internet Services - Google fiber project.
f) APIs - Google APIs are a set of programming interfaces which allows communication with Google Services and their integration to other services.
a) It enables safe search to filter out content.
b) You can browse the web in private
c) Access can be changed for various apps.
Google's mission is to organize the world's information and make it universally accessible and useful.
Note - Google.com is most searched website in the world.