The Unity Standard Assets contain a lot of things which make Game Development easier.
In my Unity Tutorial series you may need it.
This you can use if you want to create a "First Person" Game.
The Asset contain 2 different kinds of "First Person Character Controllers"
I prefer the FPSController because i find it has better and smoother movements.
The RigidBodyFPSController is based on the "RigidBody" element in Unity3D.
This you can use if you want to create a "Third Person" Game. The Asset contains 2 different kinds of "Third Person Character Controllers"
The ThirdPersonController you can use if you want that you can controll the "Player Controller" with keypad or a Gamecontroller.
The AIThirdPersonController you can use if you want that the "Player Controller" move to selected points.
This you can use if you want to create a "Car racing" Game.
The Asset contain 2 different kinds of "Car Controllers"
The Car you can use to controll the Car with your Keypads or Controller
The CarWaypointBased you can use if the Car have to drive to different Waypoints. For example as "Enemy"
This you can use if you want to create a "Aircraft" Game.
The Asset contain 4 different kinds of "Aircraft Controllers"
The AircraftJet you can use if you want to fly the "Jet" with your Keypad - Controler.
The AircraftJetAI you can use if you want that the "Jet" will fly along Waypoints.
The AircraftPropeller you can use if you want to fly the "Propeller Aircraft" with your Keypad - Controler.
The AircraftPropellerAI you can use if you want that the "Propeller Aircraft" will fly along Waypoints.
The Particle Example Prefabs you can use to make your game look more "high definition" or for "sfx".
The Asset contain 17 different kinds of "Particle Examples"
This you can use if you want to create a Game where you can use a Ball as Movement Controller.
The Asset contain 1 kind of "Rollerball Controller"
This you can use if you want to create a "2D Platformer" Game.
The Asset contain 12 kinds of "2D Platformer" Objects
The CharacterRobotBoy you can use if you want to move a basic "2D Movement Controller" with your Keypad - Gamecontroller.
The CollisionSlider is a invisible 2D Collider.
The CratePink is a pink object which has gravity.
You can use ExtentsLeft and ExtentsRight to prevent that the Player will fall of the World.
The "Killzone" object you can use to "Kill the player" for example if he should fall of the World.
The part 7-12 are different kinds of floor you can use.
This you can use if you want some basic Camera Rigs.
The Asset contain 4 kinds of "Camera Rigs"
The CctvCamera you can use that the camera will follow objects. On Standard it will follow the Player Target.
The FreeLookCameraRig you can use that the camera can Freelook around a Targer. On Standard the Player Target.
The HandheldCamera you can use for Handheld platforms.
The MultipurposeCameraRig is like the FreeLookCameraRig but you can use some more Settings.
The Cross Platform Input you can use to controll "Player Objects" with a Smartphone for example.
The Asset contain 5 kinds of "Cross Platform Input"
Personally i often use the "First Person Chraracter Controller" because you dont need to write a "complicated" script first, you can directly use it without coding.
The Asset contain: