I would make it short and simple, so that people who are non-familiar with computer science world can get along.
Computer Science, is a rapidly evolving field and is applied in almost all the Sectors, including Health, Education, Marketing and many more. Data analytics, Automation, Artificial intelligence, Machine learning, Deep learning are a few examples of applied forms of computer science.
Computer Science, in simplest term is a study of computing.
It is not just about computers, however, it also includes the study of mathematics, problem solving and the approach to solve a problem in a systematic and faster manner.
Systematic, step-by-step instructions to solve any problem are called an Algorithm.
Language of a computer
As we all understand specific language/languages, Computers also have their own language, which is called Binary.
To understand the need of Binary, we first need to understand how the computer operates. For any Computer to remain operational, we require to supply electricity in it. Electricity is the only physical input to a computer.
If we take an example of an electric switch, it can either be switched OFF or ON. Computer consists many tiny switches inside of it which can either be set to OFF or ON. Where OFF means No Electricity or Zero, and ON means Some Electricity or One.
Thus, Computers make use of the same electricity to represent and store data in form of Zero’s and One’s. So computer’s vocabulary is very limited and it only understands two digits, i.e. 0 and 1.
Binary, is written in form of 0’s and 1’s, known as binary digits or bits. For Example,
If I would like to write a numeric number 5 in binary, I would write it as 101. Or if I want to write an English letter ‘A’ in binary, it would be written as 01000001.
As, we, human, have a number system with base 10, consists the following 10 numbers.
where we define a number and its place value from right to left with 1’s digit, 10’s digit, 100’s digit, 1000’s digit and so on, Or we can say 10⁰ digit, 10¹ digit, 10² digit, 10³ digit respectively and so on .
Same way, computers have a Binary number system with base 2, consists the following 2 numbers:
where we define a number and its place value from right to left with 1’s digit, 2’s digit, 4’s digit, 8’s digit and so on. Or we can say 2⁰ digit, 2¹ digit, 2² digit, 2³ digit and so on.
Introduction to Programming
Since, Computers only understand 0 and 1, thus, there must be something in between to translate the human instructions into binary language to make computers understand what to do. That translator is called an Interpreter.
The instructions that we give to computer to solve a problem are not written in human languages like English or Hindi. However, these are usually written in Programming Language, which are easier to translate into Binary Language or Machine Code. An Interpreter is used to convert Programming language (Source code) into Binary Language (Machine Code).
A Few known programming languages are :
C, Java, C++, Python etc.
Each programming language has its unique syntax, however the underlying logic and step-by-step approach of resolving a problem remains same.
A good Program, regardless of any language, should be concise, non-repetitive, and efficient. For Example, Like we write essays in English. If our sentences are repetitive and highly complex, the essay is not considered good.
Same way, we need to make sure our programs should also be non-repetitive and optimized in terms of its Running Time and Memory utilization.
Some basics for every programming language are as below :
Functions ( Block of code to perform a specific task )
Conditions ( if or else statements )
Boolean Expressions ( True or False )
Loops ( To repeat or iterate some task for specific number of times or Forever )
You can choose any programming language to start with.
Not to forget, Problem solving skills and Mathematics are going to help you learn better in this field.
There are other concepts in Programming, like OOPs(Object Oriented Programming), which helps in writing programs for real world scenarios in easier and concise way. For Example: In real world, everything is considered as an Object, and each object has its own characteristic and features. We can also club few Objects, which have same characteristics, together to categorize or classify them in same category. That classification will be called as their Class. Like all human beings may fall into same category or classification i.e. Human Class.
High Level Languages like Python, Java, C++ etc. support OOP and can be written in terms of Classes and Objects. Where Classes define the classifications of Objects in terms of their characteristics and functions that can be performed on those objects.
Just like every other skill, programming also require practice. Patience and consistency will help you keep going.