WAP (Wireless Application Protocol) allows users to access the internet from mobile devices like phones. It uses a layered protocol stack including WDP, WTP, WSP, and WTLS to transport data securely and reliably over wireless networks. The WAP architecture includes WAP clients, gateways that encode/decode content, and origin servers hosting applications and content. WAP browsers on devices use WML (not HTML) to display simplified web pages optimized for small screens. This allows users mobility and access to services like banking, email, and commerce from any location.