Update index.md (#20535)

* Update index.md

Some improvisation and obvious corrections.

* fix: formatting

guide/english/c/file-handling/index.md

@@ -4,7 +4,7 @@ title: File Handling
 ## File Handling
 
 ### Introduction
-If you've written the C `helloworld` program before, you've already done file IO in C!  Congratulations! :tada:
+If you've written the C `helloworld` program before, you've already done file INPUT/OUTPUT(Genrally reffered as IO) in C!  Congratulations! :tada:
 
 ```c
 /* A simple hello world in C. */
@@ -21,20 +21,23 @@ int main() {
 }
 ```
 
-File Handling is most important part of a programmer . In C language we use a structure pointer of a file type to declare a file
+File Handling is one of the most important part of a programming . In C language we use a **FILE** type structure pointer  to declare a **file**.
 
 ```c
 FILE *fp;
+..// declaration of file name as fp
 ```
 C provides a number of build-in function to perform basic file operation
 
 **fopen()**   **-**   **create a new file or open a existing file**
 
 **fclose()**   **-**   **close a file**
+//Most important part is to close the file to restrict any further changes.
 
 **getc()**   **-**   **reads a character from a file**
 
 **putc()**   **-**   **writes a character to a file**
+//getc and putc() both method are are used for string or char arrays.
 
 **fscanf()**   **-**   **reads a set of data from a file**
 
@@ -60,10 +63,13 @@ C provides a number of build-in function to perform basic file operation
   
   In C there are many mode for opening a file 
   **r**  **-**   **open a file in reading mode**
+  ..//Provide access only to read a file but not to write it.
   
   **w**  **-**   **opens or create a text file in writing mode**
+  ..//Provides access only to write on file not to read it.
   
   **a**  **-**   **opens a file in append mode**
+  ..//Provides acces to append more words in file.
   
   **r+**  **-**   **opens a file in both reading and writing mode**
   
@@ -105,11 +111,11 @@ So how does this relate to `helloworld` and file IO?
 
 When you call `printf`, you are really just writing to a special file called `stdout`, short for __standard output__.
 `stdout` represents, well, the standard output as decided by your shell, which is usually the terminal.
-This explains why it printed to your screen.
+This explains why it printed to your screen. `stdout` is stream used by O's to display the output on the monitor or particularly in your terminal.
 
 There are two other streams (i.e. files) that are available to you with effort, `stdin` and `stderr`.
-`stdin` represents the __standard input__, which your shell usually attaches to the keyboard.
+`stdin` represents the __standard input__, which your shell usually attaches to the keyboard in terms via keyboard service to console.
-`stderr` represents the __standard error__ output, which your shell usually attaches to the terminal.
+`stderr` represents the __standard error__ output, which your shell usually attaches to the terminal but this time to display **errors**.
 
 ### Rudimentary File IO, or How I Learnt to Lay Pipes
 Enough theory, let's get down to business by writing some code!