Phone messages refer to communication sent via a mobile phone, such as text messages or multimedia messages. Text messages, also known as SMS (short message service) messages, are composed of up to 160 characters and can be sent to any mobile phone. Multimedia messages, also known as MMS (multimedia messaging service) messages, are composed of images, audio, video, and text and can be sent to any mobile phone. Both types of messages are sent through cellular networks and require a subscription to a mobile phone service provider.