when i have only 4 web pages running ,when look in task manager it showing 16 or 17 processes running for Firefox ..different then before,, just started after update for Firefox about 3 weeks go.. thanks for any info

There has been a slow rollout of Fission (Site Isolation) in Firefox, so if you notice you have more content processes than in the past then you might have been selected to participate in this experiment and have Fission enabled. Fission is about a new site isolation architecture in Firefox and you will see more Firefox processes running than before and when Fission is enabled you can no longer limit the number of content processes.. You can check the current Fission state on the "Help -> More Troubleshooting Information" (about:support) page (search for Fission).

• https://hacks.mozilla.org/2021/05/introducing-firefox-new-site-isolation-security-architecture/
• https://wiki.mozilla.org/Project_Fission