The Tor Browser is slow* because it
routes data via three relays (servers) for your privacy. Regular connection, on the other hand, just connects you straight to the website/service, making it much faster.
Hold on, I have a car analogy:
- A regular connection is like driving down the quickest road from point A to point B with no interruptions.
- A VPN (or proxy) connection is like having to hit point C before going to B, and C might be way off the quickest route.
- A Tor connection makes you hit points C, D, and E, which can be scattered anywhere on the map, and you may need to do some off-roading.