What does SMS /MMS stand for?????

• Use Messages on your iPhone, iPad, or iPod touch - Apple Support

Use Messages on your iPhone, iPad, or iPod touch. You can use Messages to ...

Learn the difference between iMessage and SMS/MMS. Personalize your messages ...

//support.apple.com/en-us/HT201287

• SMS - Wikipedia

Short Message Service (SMS) is a text messaging service component of most telephone,

World Wide Web, and mobile telephony systems. It uses standardized communication ...

https://en.wikipedia.org/wiki/SMS

• Multimedia Messaging Service - Wikipedia

Multimedia Messaging Service (MMS) is a standard way to send messages that include

multimedia content to and from a mobile phone over a cellular network.

https://en.wikipedia.org/wiki/Multimedia_Messaging_Service

Good luck & happy trails! 🙂

In what context is your inquiry?

You essentially have two replies, and there are different levels of answers

depending on what the question really pertains to in regard to end users.

Apple support has additional linked articles that may be helpful within

the realm of their implementation of these technologies; some answers

may relate to the provider of these services where you have an account.

Should you have any other questions, please post them.

Good luck & happy trails! 🙂

SMS means "Short Message Service" and MMS means "Multi-Media Messaging Service".

https://en.wikipedia.org/wiki/SMS

https://en.wikipedia.org/wiki/Multimedia_Messaging_Service