Short Message Service (SMS) is a service available on most digital mobile phones (and other mobile devices, e.g. a Pocket PC, or occasionally even desktop computers) that permits the sending of short messages (also known as text messages, or more colloquially SMSes, texts or even txts) between mobile phones, other handheld devices and even landline telephones. The term text messaging and its variants are more commonly used in North America, the UK, and the Philippines, while most other countries (Russia, for example) prefer the term SMS. Text messages are often used to interact with automated systems, such as ordering products and services for mobile phones, or participating in contests. There are also many services available on the Internet that allow users to send text messages free of charge.
SMS is widely used for delivering digital content such as news alerts, financial information, logos and ringtones. Such messages are also known as premium-rated short messages (PSMS). The subscribers are charged extra for receiving this premium content, and the amount is typically divided between the mobile network operator and the value added service provider (VASP) either through revenue share or a fixed transport fee.
Premium short messages are increasingly being used for "real-world" services. For example, some vending machines now allow payment by sending a premium-rated short message, so that the cost of the item bought is added to the user's phone bill or subtracted from the user's prepaid credits.
A new type of 'free premium' or 'hybrid premium' content has emerged with the launch of text-service websites. These sites allow registered users to receive free text messages when items they are interested go on sale, or when new items are introduced.