This is what every website sees of you.
Your browser sends this with every request
A site can read this with JavaScript
Why does my browser pass this on?
Part of it is needed to show a page properly: the language for the right translation, the screen for the right layout. Other details are there for features such as a dark appearance. Together they do form a recognisable profile.
What is a browser fingerprint?
Each detail above is nothing special on its own. The combination of browser, screen, time zone, languages and hardware often is. Advertising companies use that combination to recognise you without cookies.
How do I pass on less?
Firefox and Brave deliberately make many of these details vaguer. A VPN hides your IP address from the site, but changes nothing about what your browser tells. Turn on Global Privacy Control in your browser to let sites know you do not want to be tracked.
And my passwords?
A website does not see those, except the password you enter there yourself. So use a different password for every site. At wachtwoordje.nl you can create one and check whether a password has leaked.