multi point fuel injection
Heh, I guess i can answer that, honestly id rather have my colleagues answer something else , no offense.
The carbuerator utilizes something called the venturi effect. The air passes through a parabolically shaped cone which has a fuel resevoir attached to it. as the air goes through the cone the cross sectional area is decreased and as a result of bernoulli's equation. The velocity of the air increases and the pressure decreases. The low pressure region of the carb is right next to the fuel reservoir and the gas is sucked in as a result of this low pressure region. As more air passes through its velocity increases and more gas is pulled in with the resultant lower pressure. It is designed to increase the amount of gas delivered as the amount of air increases to maintain a constant stoichiometry as my colleagues have said.
Fuel injection is basically a needle in a chamber somewhere in the intake manifold somewhere near the head. The needle is attached to a solenoid which moves it back and forth at a certain oscillation. fuel is delivered in front of the needle and the needle pushes it in and in the process atomizes it. The movement of the needle is controlled by a computer because it is an electronic device.
The thing about this that makes it better is the throttle response
When you press the gas even a little bit, the car has an instant acceleration. With a carbuerator it takes a little while for the low pressure to build up. That's why if you look back 10-15 years, cars started being much much faster accelerating , they didnt lose those 1 or 2 seconds that it took to build up pressure. If you ever get to drive a non EFI car you'll know what I mean. I recently got the opportunity to try it when I was moving an old mercedes SL class at my uncle's shop. It took a second, but after that, the thing flew.