Why does the number of results in Google can sometimes drastically depend on the browser? (e.g., 61,800,000 results vs 78 results) [duplicate]

Why does the number of results in Google can sometimes drastically depend on the browser? (e.g., 61,800,000 results vs 78 results)

E.g., with the query "By the end of today", on Chrome:

on Firefox:

Both screenshots are from the 1st page.