Consider a computer connected to the Tor network through the Tor Browser Bundle: my question is does the whole internet traffic go through the Tor network like windows update, kaspersky update, vlc update or if I'm watching a video on YouTube in Tor browser does only that video data traffic get encrypted?.
The answer is NO. Tor is not a routing(i.e. OSI Layer 2 or 3) software, and TBB is just a browser. Tor itself opens a SOCKS proxy service for Layer 3+, and TransPort, i.e. transparent proxy, for Layer 3 alone. You can route all the traffic through Tor, but you need to elaborate by yourself a component to utilize tor's service ports: usually you use a firewall + TransPort for tasks like this. That's actually why you can configure which kind of packet forwarding format it will expect ( via
TransProxyType directive in torrc)