On any SO page, the page automatically tells me if there is any update. That is, the information "There is one issue with an update" or so is automatically displayed on the page.
I was curious how this was implemented. I opened my Chrome browser, opened the developer tools, the "Network" tag, but I do not see any request to the server, although information appears about a new update issue.
What is the technique to achieve this behavior? Server load? Web socket? Don't browser tools show such actions?
EDIT Also, when I click on the information "one question with the update", a new question appears, but in the developer’s tools I don’t even see the question (text) transferred. I only see that the icon (PNG) is being retrieved from the server, which is the user icon asking this question. So how is the question conveyed?
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