On iPhone and iPad, the “Messages” app combines both features. The classic Text message is shown in green, an iMessage is usually highlighted in blue.
An SMS is delivered as usual via the cellular network. An download imessage windows concept is sent online.
An SMS can be received by every cellular phone owner. An iMessage can only just be sent to owners of Macintosh, iPhone, iPad and ipod itouch.
Your iOS product instantly detects if the recipient can get an iMessage. If this is not the case, a classic SMS will be delivered.
Whether you mail an iMessage or an Text message, you often see in the text field (see photo).