From Wikipedia
An action-adventure game is a video game that combines elements of the adventure game genre with various action game elements. It is perhaps the broadest and most diverse genre in gaming, and can include many games which might better be categorized under narrow genres. The first known game in this genre is the Atari 2600 game Adventure (1979).
With the decline of the adventure game genre from mainstream popularity, the use of the term (and the hybrid term "action-adventure") has been more liberal. It is not uncommon for gamers to apply the term "adventure" or "action adventure" to describe the genre of fiction to which a game belongs, and not the gameplay itself, sometimes to the dismay of adventure game purists.
There is a distinction between thematic genres and gameplay genres, as in this case they have very different meanings and etymology. "Adventure" is a reference to Colossal Cave Adventure and has no thematic or narrative meaning nor any connection to adventure movies. Similarly, while action games usually do have violent themes similar to action movies, this is not a requirement.
Action-adventure is a hybrid genre, and thus the definition is very inclusive, leading it to be perhaps the broadest genre of computer and video games. Typically, pure adventure games have situational problems for the player to solve, with very little or no action. If there is action, it is generally confined to isolated minigames. Pure action games have gameplay based on real-time interactions that challenge the reflexes. Therefore, action-adventure games engage both reflexes and problem-solving, in both violent and non-violent situations.
From Wikipedia
Survival horror is a subgenre of action-adventure video game inspired by horror fiction. These games make the player vulnerable by providing them with less ammunition and fewer heavy weapons than other action games. Although combat is a part of the gameplay, the player must ration ammunition by evading enemies and avoiding direct confrontation. The player is also challenged to find items that unlock the path to new areas, and solve puzzles at certain locations. Games make use of strong horror themes, and the player is often challenged to navigate dark maze-like environments, and react to unexpected attacks from enemies.
From Wikipedia
Stealth game is a video game genre in which the player must avoid detection, using stealth to evade or ambush antagonists. Games in the genre employ mechanics such as hiding in shade, disguises, and noise which can alert enemies. Some games allow the player to choose between a stealthy approach or directly attacking antagonists, perhaps rewarding the player for greater levels of stealth. The genre has employed espionage and counter-terrorism themes, with such protagonists as special forces operatives, spies, and ninjas. Some games have employed stealth game elements with those of other genres, such as first-person shooters or platform games.