Some parts of this page have been copied from Fang's BEAM Robotics website, because I didn't have enough time to write up everything myself. So give him credit for this section, not me.
BEAM is an acronym for:
BEAM robotics is the use of simple electronics to create some very elegant mechanical
animals that act the same way they do in nature. The simplicity of BEAM allows people of
all skill levels to create very complex autonomous robots without learning endless fields
of electronics and without having to know how to program. If you are able to straighten
out a paperclip until it can roll down an incline plane you can build a beambot. The
potential for progressive learning makes BEAM an excellent hobby for young children who
can learn basic construction techniques and mechanics, with parental aid of course, and
move up to the electronics portion when they are ready.
BEAM devices come in infinite shapes and sizes. Some have wheels, some have legs, some even
have wings and there are some which use completely different modes of transportation. The
brains used to control BEAM "lifeforms" are very simple compared to the rats-nets of wiring
and circuitry in conventional robots. These brains, also called nervous networks, contain
no microprocessors with many BEAM critters having less transistors than a common radio. By
wiring in basic sensors to influence the nervous network, we can control how the robot
behaves much like putting blinkers on a race horse to make it run straight. These sensors
include light detectors, touch feelers, heat sensors and just about anything you can think
of. Your imagination is the limit.