WhatsApp is a popular messaging app that allows users to send text messages, voice messages, make voice and video calls, and share images and documents over the internet. It works on smartphones and computers and uses Wi-Fi or mobile data, making it often more affordable than traditional SMS. WhatsApp encrypts messages for privacy and is widely used for personal and group communication, overcoming geographical barriers. It’s available for free, with optional features for businesses. Overall, WhatsApp has transformed how people connect and communicate globally.