Role Playing Games/Types of RPGs
One common way of differentiating RPG is by setting. Common settings are Science Fiction, Contemporary, Historical, Fantasy, or some mixture of these.
For example, Mass Effect and Cyberpunk 2020 are science fiction series. The Fallout series is primarily science fiction, with light touches of Fantasy. A game like Shadowrun is nearly half science fiction and half fantasy.
Some games take place in a setting which is either meant to mirror the real world, or at least be similar to it, such as The Escapist or to a lesser extent Heavy Rain. A game like Vampire: The Masquerade uses both a contemporary setting and a fantasy setting, and integrates separation between the two into gameplay.
Some fantasy RPGs include a typical game of Dungeons and Dragons. This genre also includes Dragon Age and The Elder Scrolls, among other series.
Next to discuss is Text Adventures.