What is a function ?
Function (verb) means operating in a particular or proper way.
In programming, a function is a set of instructions in the form of statements to operate or do a work.
main function = main + function
With the name, we can say a main function is the function which is main.
The compiler starts converting instructions to bytecode from main function. So main function is the function which starts the program. i.e it is said as a main function.
So we have to give instructions in main function.
Don't worry if you didn't understand this, you can work this and see in next topic.