From NetFlix:

Nominated for two Golden Globes, this unnerving sci-fi thriller stars Leonardo DiCaprio as Dom Cobb, who earns a tidy sum infiltrating the dreams of corporate titans to steal their most closely held secrets. Tapped by a rich industrialist (Ken Watanabe) for a job involving a rival’s heir, Cobb marshals a team of specialists that includes his right-hand man (Joseph Gordon-Levitt), an architecture student (Ellen Page) and a chemist (Dileep Rao).

A dream within a dream within a dream !!! Well, if you are comfortable with computer recursion or computer stacks or maybe just plain old multiprocessing, why not ?

Just let your mind go, enjoy the eye candy (pseudo-science, dreamscapes, elaborate settings, digital effects, etc), and if you don’t seem to understand everything, it just doesn’t matter.

You might try reading the Wikipedia explanation.

At the very least pay attention to the meaning of the spinning top so that you can truly appreciate the final 5 seconds of the film.