"Recce" is military-speak for reconnaissance, and recce troops provide the "eyes and ears" of the main force for which they work.
In Canada, the Coyote is the primary Regular Force recce vehicle. You can read about it here:
http://www.army.forces.gc.ca/lf/English/2_0_42.asp?uSubSection=42&uSection=1
Essentially, it uses surveillance radar and thermal devices to pinpoint the enemy and direct other forces to engage. The vehicle is also equipped with a fairly powerful 25 mm cannon, largely for self-defence.
In the Reserve Force, recce units currently use the Iltis, but will transition fairly soon to a specialized variant of the Light Utility Vehicle (Wheeled) or LUVW. You can read about it here:
http://www.forces.gc.ca/site/feature_story/2004/feb04/09-2_f_e.asp
Reserve Force recce doesn't use the same level of surveillance equipment as the Coyote and is required to put "eyes on" their targets as a result. Our procedures are slowly developing to coordinate the surveillance capabilities of the Coyote with the instant reporting and detail provided by the "close" recce within Regular Force infantry battalions and Reserve Force armoured units.
Once a recce unit has contact with the enemy, the task is to feed back information on his intentions and dispostion or, sometimes, to engage with artillery, air strikes or attack helicopter aviation.
Essentially, though, recce's job is to seek out and provide information about the enemy. It isn't supposed to get into a knock-down, drag-out fight. Instead, recce units have information is their weapon and recce is invaluable to deciding what forces to employ, when, where.
As for infantry, the infantry's job is to close with and destroy the enemy. In the Regular Force, the infantry is equipped with armoured personnel carriers (APCs) that carry them close to the enemy and provide fire support after the soldiers "dismount" and engage in battle. In the Reserve Force, the role is identical, except that Reserve units do not use APCs and instead are largely footborne.
Hope this helps.
