The question mark separates the main part of the url from the query string. In the string hl=en the hl stands for host language and en stands for English.

The Basics of Google search URL Parameters They can be added directly to the search query URL or through the advanced search settings on the Google search page. Some common URL parameters include "q" for the search query, "hl" for language, "geo" for location, and "tbs" for the time-based search.

This is for a good reason. About half the people searching with Google are multilingual and often search in a language that doesn't match their settings. Instead, Google Search considers all these settings and other factors to automatically determine what languages would be most helpful to show results in.

Google uses "geolocation" to determine where in the world you are, so it can give you a personalized experience. This includes using the language it thinks you prefer, and it also includes giving you different results on your queries.