What is a System?

It is a set of instructions working together as parts of a mechanism or an interconnecting network, a complex whole. It is also a set of principles or procedures accordingly to which things are accomplished as an organized scheme ****or method.

A system can be“Natural” or “Engineered”. Solar System is a natural system. A Telephone network system, power plants, etc. are Engineered. An Engineered system is typically built using a structured design, skilled teams, thoroughly reviewed processes or programs, and efficient communication among all the stakeholders. All Systems have boundaries. These boundaries define the scope and intent of a particular system.

What is a Software?

Computer programs and associated documentation. Software products may be developed for a particular customer or may be developed for a general market. It is written using programming languages. A programming language has syntactic + semantic rules, otherwise called asSyntax, logical, and/or runtime errors. Programming languages are widely divided into three types.

1. High-Level Language - A high-level language is a programming language designed to simplify computer programming. It is ``high-level'' since it is several steps removed from the actual code run on a computer's processor. High-level source code contains easy-to-read syntax that is later converted into a low-level language, which can be recognized and run by a specific computing device. C, C++, Java, Python are few examples.
2. Assembly Language - An assembly language is a low-level programming language designed for a specific type of processor. It may be produced by compiling source code from a high-level programming language (such as C/C++) but can also be written from scratch. Assembly code can be converted to machine code using an assembler. mnemonic-based based codes like ADD, SUB, MOV etc.
3. Low-Level Language A low-level language is a programming language that provides little or no abstraction of programming concepts and is very close to writing actual machine instructions. Two examples of low-level languages are assembly and machine code. Native Language of Computer Circuitry is one example of a low-level language.

Program Execution

Most programs are written by programmers are in a high-level language such as C, Perl, or Java. Just as a human language makes it easy for people to communicate with one another, so computer languages simplify the job of telling a computer what to do. However, because a computer only understands numbers, talking to one is like speaking to someone with whom you don't share a language. You need a translator to properly communicate, and that's what interpreters and compilers do. Compiler and Interpreter are two different ways to execute a program written in a programming or scripting language.

Compiler - It takes entire program and converts it into object code which is typically stored in a file. The object code is also referred to as binary code and can be directly executed by the machine after linking. Compiled languages are used for developing application software. C and C++ are examples.

Interpreter - directly executes instructions written in a programming or scripting language without previously converting them to object code or machine code. Interpreted languages are used for developing system software. Perl and Python are examples.

Software System - It is engineered and can be defined as a "consists of a number of separate programs, configuration files, which are used to set up these programs, system documentation, which describes the structure of the system, and user documentation, which explains how to use the system". The practitioners involved with developing software products, i.e., the software that can be a customer are called Software Engineers.

Example of a Software System - UPI Payments - Source: NPCI

The above figure describes the detailed overview of the Universal Payment Interface (UPI) developed by the National Payments Corporation of India. UPI is a system that powers multiple bank accounts into a single mobile application (of any participating bank), merging several banking features, seamless fund routing & merchant payments into one hood. It also caters to the ``Peer to Peer'' collect request, which can be scheduled and paid as per requirement and convenience. It is one good example of a comprehensive software system.

Basic Computing Device - Computing devices are electronic devices that take inputs, process the inputs, and then calculate results from the inputs. These are the mathematical devices that can do math much in a faster way. One of the most prevalent computing devices is the computer which we all know about it. A primary computing device should contain an Input/Output Unit, a memory unit (can be primary/secondary/tertiary), a processing unit, and interconnecting structures. The computation power of a computing device can be assessed based on the Organization of Hardware, Mode of processing, Storage, Speed, Complexity, Control Mechanism, Resilience.

A Basic Computer Architecture

The above figure is the architecture of a basic computer. It includes CPU - refers to Central Processing Unit, I/O module for Input/Output processing, Main Memory for loading instructions, and System Bus which acts as connectors of all these components. A CPU primary contains the following parts -