diff --git a/EncapsulationDemo.java b/EncapsulationDemo.java
new file mode 100644
index 0000000..ccf8bfc
--- /dev/null
+++ b/EncapsulationDemo.java
@@ -0,0 +1,23 @@
+// A class that is fully encapsulated
+
+public class EncapsulationDemo {
+    private String name;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}
+// A java class to test the encapsulated class
+
+class Test {
+    public static void main(String arg[]) {
+        EncapsulationDemo n = new EncapsulationDemo();
+        n.setName("Robert");
+        System.out.println(n.getName());
+    }
+}
\ No newline at end of file
diff --git a/Multithreading/MultithreadingUsingRunnable.java b/Multithreading/MultithreadingUsingRunnable.java
new file mode 100644
index 0000000..c9aa9b9
--- /dev/null
+++ b/Multithreading/MultithreadingUsingRunnable.java
@@ -0,0 +1,25 @@
+// Java code for thread creation by implementing
+// the Runnable Interface
+
+class MultithreadingDemo implements Runnable {
+    public void run() {
+        try {
+            // Displaying the thread that is running
+            System.out.println("Thread " + Thread.currentThread().getId() + " is running");
+        } catch (Exception e) {
+            // Throwing an exception
+            System.out.println("Exception is caught");
+        }
+    }
+}
+
+// Main Class
+class Multithread {
+    public static void main(String[] args) {
+        int n = 8; // Number of threads
+        for (int i = 0; i < n; i++) {
+            Thread object = new Thread(new MultithreadingDemo());
+            object.start();
+        }
+    }
+}
\ No newline at end of file
diff --git a/PolymorphismDemo.java b/PolymorphismDemo.java
new file mode 100644
index 0000000..bc39fe4
--- /dev/null
+++ b/PolymorphismDemo.java
@@ -0,0 +1,32 @@
+public class MultiplyFun {
+
+    static int Multiply(int a, int b) {
+        return a * b;
+    }
+
+    static double Multiply(double a, double b) {
+        return a * b;
+    }
+
+    static int Multiply(int a, int b, int c) {
+        return a * b * c;
+    }
+
+    static double Multiply(double a, double b, double c) {
+        return a * b * c;
+    }
+}
+
+class Main {
+    public static void main(String[] args) {
+
+        System.out.println(MultiplyFun.Multiply(2, 4));
+
+        System.out.println(MultiplyFun.Multiply(5.5, 6.3));
+
+        System.out.println(MultiplyFun.Multiply(2, 4, 6));
+
+        System.out.println(MultiplyFun.Multiply(5.5, 6.3, 8.9));
+
+    }
+}
\ No newline at end of file