In the last lesson, we learned **what Selenium is**. Now let's understand what happens behind the scenes when Selenium automates a browser. 🤖🌐 ## 🧠 The Basic Idea When you write Selenium code, your program doesn't directly control Chrome or Firefox. Instead, Selenium communicates with the browser through a **WebDriver**. Think of it like this: **Your Test Code → Selenium WebDriver → Browser → Web Page** For example: ```text Python Test ↓ Selenium ↓ ChromeDriver ↓ Google Chrome ↓ Web Application ``` Selenium sends instructions such as: 👉 Open this URL 👉 Find this button 👉 Enter this username 👉 Click Login 👉 Verify the dashboard The browser then performs those actions. --- ## 🔍 Step 1: Your Test Code You first write a test using a programming language such as Python, Java, or JavaScript. Example: ```python driver.get("https://example.com") ``` This tells Selenium: > "Open this website." --- ## 🌐 Step 2: Selenium Sends the Command Selenium takes your instruction and communicates with the appropriate browser automation interface. For example: ```text driver.get() ↓ Selenium ↓ Browser automation interface ``` --- ## 🌍 Step 3: The Browser Executes It The browser receives the command and performs the requested action. For example: ```text Open URL ↓ Chrome navigates to the website ↓ Page loads ``` --- ## 🎯 Step 4: Selenium Finds Elements Suppose your login page contains: ```html <input id="username"> ``` You can locate it using Selenium: ```python driver.find_element(By.ID, "username") ``` Selenium identifies the element in the page and allows your test to interact with it. For example: ```python driver.find_element(By.ID, "username").send_keys("testuser") ``` Now Selenium enters: **testuser** into the username field. --- ## 🖱️ Step 5: Selenium Performs Actions You can perform actions such as: ```text Click Type Clear Select Scroll Submit Navigate ``` Example: ```python driver.find_element(By.ID, "login").click()