Sara is an artificial inteligence that simulates being a virtual friend, Sara won't judge or critizice nor insult you. Her artificial intelligence driven by machine learning allows her to only learn the good things while talking with people who interact with her, that is to say, the more you talk with her, the more she'll learn and conversations will be a lot more fluid with time.

When you tell Sara something she doesn't understand, it all goes to a learning system so that in the future she has better answers for you. Sara is capable of maintaining a conversation inside the same context in which said conversation started.