11.3. Programming Concept

Now, what is a program concept? Now, why we say talk about a program what is a computer program? It is nothing but collection of instruction and we are going to perform those particular instruction.

Every computer program is a sequence of instructions that the computer follows to perform a specific task. Think of it as a recipe in a cookbook where each step tells the chef what to do. The program is written in a language that the computer can understand, typically referred to as 'programming language'. Every task that you want the computer to do requires a specific set of instructions or commands.

Imagine you want to bake a cake. You have a recipe that outlines every step from mixing ingredients to baking and decorating. Similarly, a program consists of step-by-step instructions for the computer to accomplish tasks.

It says that just I have written it like that hardware system are inflexible but computer is also a hardware device. We build the computer with the hardware which is nothing but your electronics component, but in general we can say that hardware systems are inflexible.

Hardware systems, like televisions, are designed to perform specific tasks. For example, a TV is made to receive signals and display them. However, it doesn’t have the flexibility to perform other functions unless modified significantly. In contrast, a computer is designed as a general-purpose device that can be programmed to perform a variety of tasks. By changing the software, we can make a computer do many different jobs, highlighting its flexibility.

Consider a Swiss Army knife. It has multiple functions (scissors, screwdriver, bottle opener), making it versatile. On the other hand, a single-function tool like a can opener only does one thing. Computers are like Swiss Army knives because we can install different software (programs) that allow them to perform a myriad of tasks.

So, when we are talking about the programming concept one of the issues or all of you know that we are having an operating system. So, when we are going to switch on our computer generally we say that we are booting up our computer. And when we say that we are booting our computer, we are booting it with the help of some operating system.

An operating system (OS) is crucial software that manages hardware and software resources, providing a way for users and programs to communicate with the computer. When you turn on your computer, the OS initiates the main functionalities, making the computer ready for use. This can involve loading necessary software and setting up a user interface, much like setting up the stage before a play begins.

Think of the operating system as the manager of a restaurant. Before customers (users) can arrive and order food (programs), the manager ensures that everything is ready: the staff (hardware) is prepared, the menu (applications) is laid out, and the environment is comfortable (user interface).

every computer or every processor is having a specific instruction set. So it depends on the overall processor and we can say we are having n number of instruction.

Each computer processor has a unique set of instructions known as its instruction set architecture (ISA). This set includes all the commands that the processor can understand and execute. When we write a program, we need to use these specific instructions to ensure the processor can perform the tasks we are requesting. It lays the groundwork for how software can leverage hardware capabilities.

Imagine each person in a different country speaks different languages. If you want to give instructions (like ordering a meal), you must speak the right language for the person to understand you. Similarly, programmers must use the appropriate instruction set for the computer to understand and execute their programs.

So, now, this is the fetch and this is execute. So, basically where from we are getting it computer works on Von Neumann’s stored program principle.

The execution of a program involves two critical cycles: fetching the instruction from memory and executing it. The fetch phase retrieves instructions stored in memory, and the execute phase runs those instructions. This cycle continues for each instruction in the program, which is why computers can process information efficiently and effectively.

Consider a teacher reading a book aloud. First, the teacher fetches (reads) a sentence from the book (fetch), then explains it to the students (execute). This process repeats for each sentence in the book. In this way, the computer continually cycles through its program, fetching and executing each instruction one at a time.

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