Basic of JavaScript

When a Program is running state(inside the Ram) is called process
let say when my RAM is 4gb one process is takes 512 mb memory and another process it takes another memory

keyword
In a programming language few word are the reserved by the language for own purpose we can not changed its meaning and repurpose them for a different usecase
for examole let ,const, if ,else etc

How we can store a value inside the variable
To store a value we used Variable
let example
let take a ram inside the ram your program have 512 mb takes called process inside the process if a bucket have 12 refering the some x then x is called variable

How to create a variable in js

Three way to create a variable in js

var =value
var marks=90;

2 let keyword
syntax:let=value
let marks=60;

3 const keyword
syntax:const=value
cosnt sdhj="djdjd"

Naming Rules for Variable creation
1 variable contain small alphabet ,captital alphabet, digit,underscroe(_) like
2 we can not space or any other special character
3 we should give meaningful names so reader can identified the name properly
4 variable name can not the start with a digit but it can have digit in between at last
5 we can not used keyword in variable

Function

it take some input they process the input and recieved as output

DataType in js

what all value are store in js
Number - 10,3,2.6,-2.6
String - are the text and save "ss" as doublequotes , 'djjd' as singlequotes ,hhhd as backtick
Boolean are o,1 means true and false

undefine Something not define yet it define the futer