Firefox accessing external sites

Hi,
 I (running Debian linux/FF 88.10 )  created a fresh profile with no data ever (never browsed using the profile ; a -no-remote option is used)

Given that firefox strives to be one of the safest browsers, I see that my local packet tracking says firefox is contacting the folllowing sites. Please could someone explain why 

server-143-204-198-84.lhr3.r.cloudfront.net
ec2-34-253-97-22.eu-west-1.compute.amazonaws.com
a92-122-188-9.deploy.static.akamaitechnologies.com
242.108.96.34.bc.googleusercontent.com
etc.,

These above are some specific websites but the question might be around those domains in common

There are no other browsers running and I am clear that these are being accessed by firefox (particularly showing itself as a process named "MainThread") 

Please could someone explain why ?
what can I do to silence firefox completely ?


Regards
Bhasker C V