You can do several things on WhatsApp Web,
Chat with your classmates/teachers without the distraction of a phone
Voice Recording
Video Calling
Receive assignments from your teachers
Send your teachers completed assignments
On your computer/laptop, open the following website: https://web.whatsapp.com
You may use any of the suggested browsers,
Google Chrome (Most Recommended)
Mozilla Firefox
Opera
Safari
Microsoft Edge
Click the Menu (three vertical dots) button on the top right of your WhatsApp App
In the menu, you will see the option to select Whatsapp Web
On iOS, click the Settings (gear icon) tab on the bottom right of your Whatsapp App.
You will then see an option to turn on WhatsApp Web/Desktop.