diff --git a/Debug/Window_practice.exe b/Debug/Window_practice.exe
index addb5e6..91dcde7 100644
Binary files a/Debug/Window_practice.exe and b/Debug/Window_practice.exe differ
diff --git a/Debug/Window_practice.pdb b/Debug/Window_practice.pdb
index b22e374..bbf9506 100644
Binary files a/Debug/Window_practice.pdb and b/Debug/Window_practice.pdb differ
diff --git a/Window_practice/Debug/Main.obj b/Window_practice/Debug/Main.obj
index 0e991b3..09a1ea4 100644
Binary files a/Window_practice/Debug/Main.obj and b/Window_practice/Debug/Main.obj differ
diff --git a/Window_practice/Debug/Window_practice.ilk b/Window_practice/Debug/Window_practice.ilk
index 20644bb..ac7fb3a 100644
Binary files a/Window_practice/Debug/Window_practice.ilk and b/Window_practice/Debug/Window_practice.ilk differ
diff --git a/Window_practice/Debug/vc142.idb b/Window_practice/Debug/vc142.idb
index 1b345f2..5849648 100644
Binary files a/Window_practice/Debug/vc142.idb and b/Window_practice/Debug/vc142.idb differ
diff --git a/Window_practice/Debug/vc142.pdb b/Window_practice/Debug/vc142.pdb
index 4311e24..2ea345a 100644
Binary files a/Window_practice/Debug/vc142.pdb and b/Window_practice/Debug/vc142.pdb differ
diff --git a/Window_practice/src/Main.cpp b/Window_practice/src/Main.cpp
index ecb93e0..f18ff2f 100644
--- a/Window_practice/src/Main.cpp
+++ b/Window_practice/src/Main.cpp
@@ -3,14 +3,15 @@
 #include <iostream>
 
 int main(void){
-    GLFWwindow* window;
-
-    // Library inits
+    // GLFW init
     if (!glfwInit()) {
         std::cout << "GLFW could not be initialized!" << std::endl;
         return -1;
     }    
 
+    //Main window
+    GLFWwindow* window;
+
     //Window creation
     window = glfwCreateWindow(640, 480, "OpenGl practice", NULL, NULL);
     if (!window){
@@ -21,6 +22,7 @@ int main(void){
    
     glfwMakeContextCurrent(window);
 
+    //GLEW init
     if (glewInit() != GLEW_OK) {
         std::cout << "GLEW Error" << std::endl;
         return -1;
@@ -28,16 +30,25 @@ int main(void){
 
     std::cout << "OpenGL version: " << glGetString(GL_VERSION) << std::endl;
 
+    //vertex positions
+    float positions[6] = {
+        -0.5f, -0.5f,  //Vertex2f
+         0.0f,  0.5f,  //Vertex2f
+         0.5f, -0.5f   //Vertex2f
+    };
+
+    //Vertex buffer(s)
+    unsigned int buffer;
+    glGenBuffers(1, &buffer); //number of buffer to generate
+    glBindBuffer(GL_ARRAY_BUFFER, buffer); //binding the buffer
+    glBufferData(GL_ARRAY_BUFFER, 6 * sizeof(float), positions, GL_STATIC_DRAW);
+
    //Main loop
     while (!glfwWindowShouldClose(window)){
         /* Render here */
         glClear(GL_COLOR_BUFFER_BIT);
 
-        glBegin(GL_TRIANGLES);
-        glVertex2f(-0.5f, -0.5f);
-        glVertex2f(0.0f, 0.5f);
-        glVertex2f(0.5f, -0.5f);
-        glEnd();
+        glDrawArrays(GL_TRIANGLES, 0, 3); //without index buffer 
 
         /* Swap front and back buffers */
         glfwSwapBuffers(window);