MMS is the technical name for sending mobile phone text messages with multimedia (images, video, sound, or files). On EchoBack MMS message contain 1-10 images that add up to a total of less than 5MB in size. Since MMS was developed after SMS was created they had the forethought that people want to send long text messages. Because of this the maximum number of characters that can be sent in one single MMS message is 1,600 characters with no need for the phones to stitch together message segments. Because of this it can often be cheaper to send an MMS message than a long SMS message.