LCD and Viewfinder
Canon 20D has a Fixed Type 1.8″ LCD screen with a resolution of 118k dots. At only 1.8″, the screen is on the smaller side and 118kdot resolution is lower than most of the recent models in this class.
20D has a built-in Optical (pentaprism) viewfinder. The viewfinder has a coverage of 95% and a magnification ratio of 0.56x. 95% coverage means that what you see in your viewfinder while shooting will slightly be different from the actual image.
Max Shutter speed
Canon 20D can shoot continuously at max speed of 5 fps and has max shutter speed of 1/8000 sec.
20D has a built-in flash, and it also has a flash shoe to mount your external flashes too.
Canon 20D features a Phase Detection autofocusing system. The AF system has 9 points to choose from.
Unfortunately Canon 20D doesn't have Video recording ability.
Connectivity and Storage
Canon 20D has a USB 2.0 (480 Mbit/sec) port to connect your camera to other devices.
Canon 20D Features Compared to Main Competitors
You can download Canon 20D's User Manual here