RCS stands for Rich Communication Services, which is a communication protocol between mobile telephone carriers and between phone and carrier, aiming at replacing SMS messages with a text-message system that is richer, provides phonebook polling, and can transmit multimedia. RCS is a revamped form of messaging that comes with a host of functionality and security features that SMS simply cannot provide. RCS offers "rich" features similar to those of messaging apps, but delivered via the preloaded SMS messaging app - for example Google Messages or Samsung Messages. Some of the key features of RCS include:

• Group chat: RCS allows users to engage in group chats with other users.
• Delivery of high-resolution photos or videos: RCS allows users to send and receive high-quality media files.
• Read receipts: RCS allows users to see when someone has read or received their message.
• Typing bubbles: RCS allows users to see when the person they’re chatting with is typing a message.
• No character limit: Unlike SMS, RCS has no character limit.

RCS is considered by many to be a more convenient and wide-ranging communications platform than SMS and even other OTT counterparts. RCS messages are sent with the Rich Communication Services (RCS) protocol over Wi-Fi and mobile data. RCS chats will be turned on only when all the participants in a conversation have RCS. RCS chats are provided by Google or your mobile carrier.