The generic name of Google’s web crawler is Googlebot. The two types of crawlers that craws your site are a desktop crawler that stimulates a user on desktop and a mobile crawler that stimulates a user on a mobile device.
Googlebot runs simultaneously by thousands of machines to improve performance and scale as the web grows. There can be logs of several machines as many crawlers are crawling a maximum number of pages possible from your site. While the entire process, cutting down the bandwidth usage is taken care of.
Usually, Googlebot used to crawl over HTTP/1.1, but now will crawl sites that can benefit from it over HTTP/2 if it is supported by the site.