RCS (Rich Communication Services) text messaging is a modern messaging standard that significantly upgrades traditional SMS/MMS by enabling features like sending high-resolution photos and videos, read receipts, typing indicators, and enhanced group chats. It works over the internet (Wi-Fi or mobile data) rather than relying solely on cellular networks

. Apple introduced support for RCS messaging starting with iOS 18. This allows iPhone users to send RCS messages not only to other iPhones but also to Android devices, bridging the messaging experience gap between the two platforms. With RCS on iPhone, users can enjoy richer media sharing, real-time typing indicators, read receipts, and better group chat management when communicating with Android users

. Key points about RCS on iPhone:

• RCS messages can be sent over Wi-Fi or cellular data.
• It supports high-resolution media, links, read receipts, and typing indicators.
• RCS messages appear as green bubbles in the iPhone Messages app, labeled as "Text Message – RCS" to distinguish them from SMS and iMessage.
• Carrier support is required to enable RCS, and major carriers like Verizon, T-Mobile, and AT&T support it on iPhone.
• RCS improves cross-platform messaging quality compared to the older SMS/MMS fallback, which limited media quality and features

In summary, RCS on iPhone is Apple's adoption of a universal, enhanced texting standard that improves messaging between iPhones and Android devices by enabling richer content, better interactivity, and a more unified experience across different smartphone platforms