Phones generally retrieve text messages automatically, and both smartphones and standard cellphones typically notify users when they've received a message. Some carriers allow users to check text messages online.
Smartphones come with a messaging app that is generally set to alert the user when it retrieves a text message. Users can access this app at any time to view saved messages or send new ones. Some carriers, such as Verizon, allow users to access messages online and send new messages from a computer. Users can also use a Google Voice number to send and retrieve messages online.
Short Message Service is a popular way to retrieve messages, as of 2015. SMS messages are often sent through a special data connection. However, carriers can send messages through the standard data lines as well. Because of this, users can sometimes retrieve text messages even if they lack a data connection.
Other messaging services provided by Facebook, Yahoo! and WhatsApp require a data connection and cannot use the data frequencies used by text messages. However, because these messages don't have to be routed through various carriers, such apps allow users to send messages to anyone with Internet access, eliminating the premiums that come with international SMS messaging.