Text messaging, or texting, is the act of composing and sending electronic messages between two or more mobile phones, or fixed or portable devices over a phone network. The term originally referred to messages sent using the Short Message Service (SMS). It has grown to include multimedia messages (known as MMS) containing images, videos, and sound content, as well as ideograms known as emoji. The service itself has different colloquialisms depending on the region. It may simply be referred to as a text in North America, the United Kingdom, Australia, New Zealand and the Philippines, an SMS in most of mainland Europe, or an MMS or SMS in the Middle East, Africa, and Asia. The sender of a text message is commonly referred to as a texter.

Text messages can be used to interact with automated systems, for example, to order products or services, or to participate in contests. Advertisers and service providers use direct text marketing to message mobile phone users about promotions, payment due dates, and other notifications instead of using postal mail, e-mail, or voicemail.