I believe the correct answer is the first option. The primary difference between 3g and 4g cellular systems would be that 4g systems have faster transmission as compared to 3g. The G would mean generation. The very difference of both is their speeds.
Answer:
Google uses automated programs called spiders or crawlers, just like most search engines, to help generate its search results. Google has a large index of keywords that help determine search results. ... Google uses a trademarked algorithm called PageRank, which assigns each Web page a relevancy score.