I heard that if someone wants to hack your computer they would need you to download a few things. Can they do that if you did not download anything? But let's say they already had some of your passwords (skype, mail etc...)
Most Helpful Guy
There are all sorts of viruses, spyware, and even browser exploits that are 'drive by' infections you get just by visiting a page.
The way to prevent this 100% is to run the OS in a non-administrator mode (logged in as a non-priviledged user or using a read-only OS like a live Linux distro) AND/OR use a script-blocking add-on like NoScript. Scripts are what infect your computer, so if you block scripts from executing, you reduce the chance some script will install malware.
Web pages have analytics built into them, and unless you are using some sort of anonymizer or proxy like the TOR service, your IP address is very trackable. Some browsers also have a
private mode that blocks some of the analytics, but the IP address can still be identified, although it's trickier to do.
I manage a web site, and I load both Google Analytics and TraceMyIP analytics on each page... I can see lots of info about who visits my site.. IP address, location, OS, browser... etc.
that should shed some light1