Check out this great map from the Oxford Internet Institute at Oxford University.
It portrays the world through internet users: the bigger the box, the larger a country's internet population. The deeper the red, the higher the internet usage of that population:
Internet Penetration via Oxford Internet Institute
The big takeaways?
China has the world's largest internet population at more than 400 million, though usage is lower there than in Japan and South Korea, as well as the U.S. and much of Western Europe.
South America is a relative internet pipsqueak, while Africa is almost nowhere to be found.
Here's how the Oxford researches explain that last point:
The map also starkly illustrates the relatively small number of users in South America and Africa. The visualization causes South America to shrink to a size that is smaller than the United States, and Africa to skew unrecognizably on the map. We also see that there are very few countries in the Global South with high Internet penetration rates. This indicates future growth in the total number of Internet users will most likely come from areas that are currently underrepresented.