get ready to read A LOT of info. here goes:
1) A processor is a type of microchip that is used to receive, process, and send out instructions and commands. it is typically made of silicon and other materials. it is capable of different working speeds, the highest i've ever seen is 4.2 gigahertz. in some cases, computers have more than one processor, such as server computers and i think supercomputers.
2) The types of processors vary between their intended purposes. for desktops that are used in a home, there are microprocessors with different "cores" inside of them. basically, the technology is designed to have more than one processor inside one single chip. i don't fully understand myself how they do this, but it makes a big difference how many cores a processor has. the weakest processors are single core microchips, the top low range/low mid range microchips are dual core, there are a few (and i do mean only a few) three core microchips. then there is four core microchips. a processor development company called AMD has managed to make six core and eight core microchips, although the most these processors ever need to use are two or three.
Still at types of processors, there is a type of processor that is used for creating what you see on your monitor. these graphics processor units (often shortened to GPU) come in the form of being built in to your motherboard, or they come in the form of "cards" that can be plugged into the PCI or PCI-Express slots on your motherboard. if you get a "graphics card" then it most often comes as a card the looks like a piece of a motherboard, with a fan attached to it so it doesn't overheat, and little gold squares on the bottom of it that connect to the PCI or PCI-Express slot. the processor part is underneath the fan. on the side there should be a metal part the has different shaped and colored plugs on it. these are the different plugs for your monitor, monitors have different kinds of plugs. the ones i've seen are D-Sub, VGA, DVI, and HDMI. you also need a big enough power unit to power both the graphics card and the rest of your system. some processors (the ones that make your computer work, also called a CPU, not the GPU) have built in graphics capabilities.
3) a CPU is used for many things. depending on what machine it is in, it does different tasks. i'll just cover the ones it does in a desktop or laptop.
In home used machines, such as desktops or laptops, a CPU is responsible for processing the commands it is receiving, and tells the other parts what to do. if you try to boot into windows, it tells the hard drive to start reading itself so you can boot up windows and log in and all that other stuff. if you try to download something, it tells the hard drive to start writing the data to itself. when you turn the computer on, it tells the graphics unit you're using to start displaying to the monitor. you get the idea. it also receives responses to these commands, to which it sends out more info. such as when windows encounters an error it cannot fix itself without interrupting your work, it sends info to the CPU which then signals it to initiate the blue screen of death. the CPU is essentially the brain of your computer. and the motherboard is all the nerves, carrying out the commands of the CPU to different parts of the computer.
4) if your CPU is damaged, such as if it's dropped, or one of the connector pins is bent, or anything else, it WILL NOT WORK. if you try to make it work, it could have drastic consequences. if you turn on a computer with a damaged CPU then it might boot up, but fail and short circuit. this could fry your entire computer. it might just simply not turn on, or turn on then shut down. but it short circuiting could happen, even though it's only worst case scenario.
well i hope i answered your questions well enough, and if you have anymore e-mail me at firstname.lastname@example.org and i'll be sure to answer them! good luck!