SMS stands for Short Message Service, which is a text messaging service that allows the exchange of short text messages between mobile devices. SMS messages typically have a maximum length of 160 characters and can be sent and received on various mobile networks. SMS is widely used for personal and business communication, providing a quick and convenient way to send concise messages to individuals or groups of people.

MMS stands for Multimedia Messaging Service, which is a way to send text messages with attached files, such as pictures, videos, emojis, or website links. A text message of up to 160 characters without an attached file is known as an SMS, while a text that includes a file becomes an MMS.

SMS is a stateless communication protocol in which every SMS message is considered entirely independent of other messages. SMS is used for M2M (Machine to Machine) communication, such as LED display machines controlled by SMS or vehicle tracking companies using SMS for their data transport or telemetry needs. SMS usage for these purposes is slowly being superseded by other technologies.

Typical use cases of SMS include sending notifications from service centers to a customer, sending a notification of delivery by e-commerce platforms, sending a notification to a mobile phone owner of a voicemail message, sending promotional messages to cell phones as part of SMS marketing, sending a notification to subscribers about their plans, and sending codes as part of a multifactor authentication platform. SMS marketing often uses SMS APIs to automate and streamline the process.