foreign ERS are made up of hardware and software Hardware are the physical components that your computer needs to do its job like the CPU Ram hard disk and keyboard software are the programs that run on your computer such as your operating system spreadsheet and video games the central brain of this computer is called the central processing unit or CPU it's the cpu's job to receive input from some device connected to the computer carry out some form of calculation and give an output to another device it can also load or save data to memory known as reading and writing this is also a form of input and output this is known as the basic computer system model as all computers follow this structure at a simple level as mentioned the CPU is the brain of your computer it is the CPU that will execute the programs that you decide to run like your operating system and software applications the CPU is made up of the control unit arithmetic logic unit and cache memory the CPU also contains small areas of fast memory called registers that have specific jobs to do modern CPUs are basically designed using the Von Neumann architecture named after the mathematician John Von Neumann Von Neumann was the first proposed the idea of a digital computer whose Central brain was broken up into small areas each having its own specific job to do a bit like a car engine the Von Neumann architecture used the idea of the stored program concept the concept is where the program is made up of instructions and data which is stored in memory and then moved one instruction at a time to the processor with the Von Neumann architecture both data and instructions are stored in the same location typically our main memory the key thing about this architecture is that the main memory must be large enough to store the program instructions as well as its data now as the Von Neumann architecture describes the CPU needs to send and receive data and instructions to and from the main memory main memory is usually held at a physically separate location on the motherboard from the CPU chip in order to move data and instructions around we need to use special connectors on the motherboard called buses buses are wires on the motherboard that connect RAM memory to the CPU chip there are three buses that we need to look at the control bus the address bus and the data bus to understand how this all works we need to understand the concept of addressable memory imagine a row of houses with no addresses Postman needs to collect a package from number 47. we have the instruction we are collecting but we don't know the House's addresses and so we don't have the package the post mode have to go through each house and work out who lived there in order to locate the package imagine now that all the houses had addresses we can find number 47 easily now as we have the address we also have the instruction we are collecting therefore we can then get the package from number 47. much like your home address each byte in main memory has an address too we use this address to find the memory location containing the programming instructions and data the address is sent along the address bus the control bus will send the instruction we are performing this could be saving something into memory like delivering a package or it could be loading something from memory like collecting a package the data bus is used to send the data we are either going to put into main memory or get out of main memory let the package we're collecting or delivering so a computer system is made up of hardware and software with input output and storage devices modern CPUs commonly use the Von Neumann architecture programs are made up of instructions and data and are stored in main memory data addresses and instructions are moved along wires called buses the control bus transmission control signals between the CPU and other components the address bus contains the address in memory of some instructions or data and the data bus transmits the data we want to load or save [Music]