The most important thing that the computer needed earlier was at least in process right and this processor was a piece of Hardware right and it was developed with a set of instructions we call them the instruction set right

so uh the CPU puts out the address give me the 1,356 bite okay so that bite right now is the next instruction that I want to execute then in the next clock cycle the memory is going to put that data out

let's say we have that up code and looking at this first 16 bits the processor can now determine what is this instruction and what its job is let's assume that particular off code indicates add now from the instruction set we can now determine that if this is an add instruction then there is a very specific meaning to all the other 16 bits

so now you must have got the idea that in order to do this ad operation it it really did not take me one clock cycle it took me a few two or three clock Cycles right because first it affects the instruction decode fetch the first op code fetch the second op code then I'll do the computation then I have to submit the result

so things are going in a pipeline I'm not just going to put one address out there and wait for the whole thing to complete because if you would do that it would just be so so much slower right because uh while the CPU is executing the buses are doing nothing so you rather use up the bus bus time

The reason why we're talking about this is depending upon who you know who is talking about it, some people like to talk about this course from a computer science perspective, some from an engineering perspective. Generally, in the Computer Sciences, we have computer organization where we focus more on the software and on the functionality, and when we have courses named computer architecture, here we care more about how is this computer system put together, what kind of processor is present, what are its instructions set, and so on.

The application Spectrum goes from single bit to multiple bits, and on one end, you have control systems, and on the other end, you have more of the computer science perspective, because you're able to do a lot more complex data processing applications.

Other than numbers, we have a boolean, and what else, you have character, you have strings, so on and so forth. If your input is numbers, obviously, you're doing numeric calculations, and then we also have symbolic computations like, for example, if a variable is a string, okay, and you want to do a string comparison.

Eventually, the computer system started to be truly a multi-purpose device, rather, we would also go as far to say this was a multimedia computing system, because you know you can have different types of data that we all process.

How would one interact with the computer, how would one provide to the computer the inputs, which will have programmed, because we need to run our programs.

I'll give you an example of what assembly looks like, right, there would be an instruction, move, okay, uh, into register one, the value, a moves into register to, some value from a particular address, B, then add, R1, R2.

so this is what we call lowlevel langage right so um initially the challenge was that there were very few computer users because he had to be a specialized user to even interact with the computer system all right it was difficult

and then uh what what happened was we added several different layers okay at the core of it was the actual processor the hardware okay and then we in order for users to interact with this Hardware we remove them one level at a time

and then we added one level of software systems say here you have your assembly but still for assembly we need to know something about the hardware we need to know how many registers we need to know how the memory is made up Etc

and then if you continue to add more levels of software it's now easier and easier for the users to basic to focus more on this region care only about the programs have things such as the operating system that does everything regarding the managing of the processor managing of memory etc

for example let's say you run a program okay and in this program you have variables okay you you allocate memory for your variables you allocate value uh for these variables and at the end you run your program and you're done okay we don't care about if I allocate a memory for my program am I freeing up that memory I don't do that because the operating system does that for me