Console commands can be used within a variety of ways within Call of Duty 4. One of the main uses of the console commands is to adjust lighting and colouring effects of the game, and is often used in cinematics. Console commands are also useful when testing mods, creating maps, or creating and reviewing replays.
I will go through and outline a number of popular commands in each respective section, but firstly I must explain how to enable to the console. To enable to console, start of the Call of Duty homescreen, and click on "Options", then "Game Options", and toggle the "Enable Console" button. Each command must start with a "/", at the start! This is very important.
To load up a level where are console commands are enabled, hit your tilde or ~ key, and type, without quotes, "devmap mp_<LEVELNAME>", where <LEVELNAME> is the name of your desired level. For example to start game on Crash where console commands, I would type "devmap mp_crash".
For movie making, their a number of powerful commands. To enable film tweaks, in which one can change the colour and saturation of the map, type "r_filmtweakenable 1". Furthermore to change sunlight effects, type "r_lighttweaksunlight <INTENSITY>" and enter an intensity from 0 to 4, or to adjust the direction of the sun, type "r_lightweaksunlight", followed by the directions of the sun on the X and Y axis. Finally, the most important command is "ui_hud_hardcore 1" to remove HUD elements.
For testing mods and creating maps, one can use powerful commands such as timescale, to shift foward the game time at an accelarated rate. For example, timescale 2, makes the game run at double the usual speed. The command ufo can be used to fly around the map, through walls and buildings, and enables you to test and check elements of your map or mods.
Finally one can record their gameplay through the use of "record <DEMONAME>", "stoprecord", "demo <DEMONAME>", these commands can be used to start recording, stop recording, and playback of a specified demo respectively.