As of today, Google has started their rollout in the United States of RCS Messaging for Android, formally known as Rich Communication Services. RCS was created in 2007 and is currently managed by the GSM Association. However, it has not found success until recently.
RCS messaging allows for numerous benefits over traditional SMS (Simple Messaging Services) and MMS (Multimedia Messaging Services, both created in the 1990s. The RCS standard allows for group chats with read recipients, location sharing, availability (presence) information and higher resolution image up to 10 MB.
In order to take advantage of the new standard on Android, you have to have Android Message as your client. Also, if the other person being messaged does not have a phone or app that supports RCS, RCS will fall back to the traditional SMS/MMS standard. This could be a problem for those who are messaging an iPhone or other iOS device through iMessage, as iMessage currently does not support RCS.
Sources: The Verge, Digital Trends, Ars Technica and Android Authority.