Strava's main objective is to keep a detailed record of all of your fitness activities. It saves all the data from your outings, such as: distance covered, time elapsed, average pace, and calories burned. All this data is saved in your personal history, which you can then share with other app users.
This social factor is precisely one of the most interesting things about Strava. The app has a large community with whom you can go beyond simply sharing your routes to actually engage in some healthy competition. Every so often Strava will have an event in your area and you can compete with other app users to be the king of that competition.
Apart from this social element, which adds a certain element of motivation, Strava also incorporates achievements, giving an additional incentive to those who enjoy showing off their trophies to the other users.
Strava is a great fitness app for users who usually go out running or biking, as it not only lets you keep a complete record of your activities, but also lets you share it with all the other users.