Google added a new keyboard shortcut to help users more quickly jump their cursor in the search entry box. If you do a search on Google.com and start typing afterwards, Google will prompt you about this keyboard shortcut that reads "Press [/] to jump to the search box."
Here is a screen shot (click to enlarge):
This was first covered by 9to5Google but Shameem Adhikarath also notified me of this on Twitter.
Google also shared this news on Friday afternoon:
Have you ever done a search and wanted to jump back to the search box quickly, in case you wanted to search differently? Now you can. On desktop, after you've done a search, just tap the / key to bring your cursor back to the search box.
— Google SearchLiaison (@searchliaison) April 16, 2021
Forum discussion at Twitter.