In describing itself, the iRobot Corporation says it ''designs and builds robots that make a difference in people's lives.'' And that is true -- in more ways than one.

The company's consumer products, which include the Roomba vacuum cleaner robot and the Scooba robotic mop, certainly make a difference by taking care of household chores.

But iRobot is also a supplier of robots to the military and law enforcement.

For that market, the cute names are dispensed with, in favor of Warrior, PackBot and Transphibian. These robots make a difference, too: they handle explosives, carry gear for soldiers and perform scouting and reconnaissance work for the military and police.

Decades (or is it years?) from now, when we are all hiding in underground bunkers, fighting a war against our newly self-aware robot adversaries, we will look back to where it all began and say, ''It was those robot mops and vacuums. We should have stopped there.''

In the meantime, here is a look at how one of our current robotic assistants gets its job done. SAM GROBART

GRAPHICS: Compact Cleaner: Measuring 6.5 inches wide by 3.5 inches tall, and weighing only three pounds, iRobot's diminutive Scooba 230 floor-cleaning robot can get into confined spaces that larger devices can't.; Cleaning Pattern: Scooba has two cleaning cycles: 45 minutes for large rooms and 20 for small areas. Using proprietary software, it makes multiple passes over the floor, spiraling and crossing the floor and following along the walls. ''Virtual walls'' create invisible barriers it will not cross.; Efficient Use of Space: Scooba owes its diminutive size to a clever water-management system that eliminates the need to have separate tanks for its clean and dirty water.; The Underside: Cleaning solution comes through tiny holes A; brushes, B, are used to scrub the floor; and dirty water is removed using a squeegee and the vacuum C. (Source: iRobot Corporation) (GRAPHICS BY FRANK O'CONNELL/THE NEW YORK TIMES)