Chat apps are software applications that allow users to send and receive messages in real-time over the internet. They can be used on various devices, including smartphones, tablets, and computers. Popular chat apps include WhatsApp, Facebook Messenger, and Telegram. These apps often support text messaging, voice calls, video calls, and file sharing. Many chat apps also offer features like group chats, stickers, and emojis to enhance communication. Some prioritize privacy and security, using end-to-end encryption to protect users' conversations. Overall, chat apps have become essential tools for personal and professional communication in today's digital world.