MMS (Multimedia Messaging Service) is the cellular protocol for sending non-text messages — images, video clips, voice notes, and group threads with multiple recipients. SMS handles plain text up to 160 characters; MMS handles everything else.
MMS works the same way SMS does from the user perspective — the phone's Messages app handles both. Recipients see images and group conversations seamlessly because both phones speak MMS.
VoIP business numbers often have limited MMS support — group messaging in particular is unreliable on virtual numbers because some carriers strip MMS metadata that VoIP services don't propagate correctly. Kelir's business eSIM is a real cellular number, so MMS works the same way it does on any personal cell line: send and receive photos, group threads with mixed iPhone/Android participants, voice notes.