Smart links are links that take the user into different paths depending on the environment where the link is opened thus making the user move forward without breaking the experience. For instance, what would happen if a user clicks on a deep link that is supposed to take him to a specific section of an app, but that app hasn’t been downloaded in this device? Broken experience. The user would be clicking without any response!
In this exact same situation, a smart link would send the user to an alternative route such as the app store, or his mobile web browser; therefore, keeping a smooth experience for the end user, and actually driving up new installs.
Smart links are able to recognize the device that is opening the link, and check if the app is installed before trying to send a user there. They also have the ability to take different paths if the app is not there.