Good evening,
Certainly here guests are people who are not signed in, this includes members who are not signed in even if they signed in recently and have signed out again.
Some member sign in and stay signed in until the system signs them out, their browser clears cookies etc, other stay signed in only as long as needed to post a message.
Well behaved bots identify themselves, when you (in this context your browser) make an http request you can include
headers, these are optional extras that were supposed to help the web server understand what was being asked for, one of these is the User-Agent
Code:
Search engines
Mozilla/5.0+(Linux;+Android+7.0;)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Mobile+Safari/537.36+(compatible;+PetalBot;+https://webmaster.petalsearch.com/site/petalbot)
netEstate+NE+Crawler+(+http://www.website-datenbank.de/)
Real users
Mozlila/5.0+(Linux;+Android+7.0;+SM-G892A+Bulid/NRD90M;+wv)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Version/4.0+Chrome/60.0.3112.107+Moblie+Safari/537.36
Mozilla/5.0+(Windows;+U;+Windows+NT+6.0;+en-US)+AppleWebKit/527++(KHTML,+like+Gecko,+Safari/419.3)+Arora/0.4+(Change:+)
This tells the web server what software will be used to display/process the result and
- A web site may decide to send a response to a search engine that doesn't include sound and video as the search engine can't use them anyway
- The Lynx browser is a text only browser so sending it a Flash element (when Flash was popular) would be pointless.
- If there is Linux in the user-agent send one type of virus and another sort for Windows. :-)
As use of the internet became more and more deskilled and commercial pressures kicked in the user-agent header has become redundant in most situations, added to which lying in this header is common.
Taken from a real web site
Code:
Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/89.0.4389.114+Safari/537.36
looks harmless but it was associated with requests to the web pages /blog/wp-includes/wlwmanifest.xml, /web/wp-includes/wlwmanifest.xml, /wordpress/wp-includes/wlwmanifest.xml which means that it was a malicious process looking to see if the site was based on Wordpress and then hopefully corrupt some key files.
Bye
Ian