correct typos and explain alert and prompt in Chrome console

Author: AkliluMihtsun

Sprint-2/4-stretch-explore/chrome.md

@@ -1,15 +1,20 @@
-Open a new window in Chrome, right click an empty space on the page, select **Inspect** from the dropdown, then locate the **Console** tab.
+Open a new window in Chrome, right click page, select **Inspect** from the dropdown, then locate the **Console** tab.
 
 Voila! You now have access to the [Chrome V8 Engine](https://www.cloudflare.com/en-gb/learning/serverless/glossary/what-is-chrome-v8/).
 Just like the Node REPL, you can input JavaScript code into the Console tab and the V8 engine will execute it.
 
 Let's try an example.
 
-In the Chrome console, invoke the function `alert` with one argument, the string `"Hello world!"`;
+Click an empty space on tn the Chrome console, invoke the function `alert` with one argument, the string `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+// The `alert` function displays a message to the user and it stops js execution until the user dismisses the alert
+
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
 What is the return value of `prompt`?
+
+// The `prompt` function opens a popup dialog and waits an input from a user. it stops js execution until the user inputs or cancel the popup dialog
+// The return value of `prompt` is a string