What is the difference between SMS and MMS text messages?

SMS stands for Short Message Service and is commonly known as texting. It’s a way to send text-only messages of up to 160 characters between phones.

MMS stands for Multimedia Messaging Service. Whenever you send a text with an attached file, like a picture, video, emoji, or a website link, you’re sending an MMS.

Source.

I think this question is related…Why are some of the message in a green cloud and some are in a blue cloud?

@smudges on iphones it indicates if the message was sent by SMS or an internet messaging protocol.

@Lightlyseared Thank you!

So…when I send a picture or video in a text does it automatically become an MMS?

Not necessarily. For example if you’re using an iPhone and the person you’re sending to also has an iPhone it will be sent as apples internet messaging protocol. Depending on your network provider you are often charged for sending MMS messages instead of using data.