Updated

- Descriptions
- Comments to the Code

Assets/Lectures/RL1.md

@@ -5,31 +5,57 @@
 ## Lecture 1 - Introducton to Rust Programming
 ![](https://img.shields.io/badge/-1st_Apr-orange)
 
+**Rust is:**
+- fast and memory-efficient
+- no runtime or garbage collector
+- rich type system
+- ownership model guarantee
+- system programming language
+- immutability and higher-order functions
 
 ### Hello World Program
 
 ```
-fn main() {
-    println!("Hello, world!");
+fn main() { // 'main' function is the entry point to the program
+
+    println!("Hello, world!"); // Macro call to println. ! denotes a macro
+
 }
 ```
+```fn``` keyword denotes a function, and the ```println!``` macro prints the message to standard output. 
+Statements in Rust are separated by semicolons.
+
+#### Compile 
+```
+rustc <<filename>>.rs
+```
+
+### Mutable Variables
 
-### Example 1 
 ```
-use std::io;
+// guessingNumber.rs
 
-fn main() {
-    println!("Guess the number!"); // Macro call
+use std::io; // use io module from standard library
 
-    println!("Please input your guess.");
+fn main() { // 'main' function is the entry point to the program
 
-    let mut guess = String::new(); // Mutable Var.
+    println!("Guess the number!"); // Macro call to println
 
-    io::stdin() // instance 
-        .read_line(&mut guess) // Ok / Err 
-        .expect("Failed to read line");
+    println!("Please input your guess."); // Macro call to println
 
-    println!("You guessed: {guess}");
+    let mut guess = String::new(); // Mutable Variable.
+
+    io::stdin() // returns the instance of 'std::io::Stdin'
+        .read_line(&mut guess) // read the input from the console and append it to guess - Ok / Err 
+        .expect("Failed to read line"); // terminates the program on any error
+
+    println!("You guessed: {guess}"); // Macro call to println
 	
 }
 ```
+
+To Compile and Run:
+```
+> rustc guessingNumber.rs
+> guessingNumber.exe
+```