Different button prompts in games

Depending on what system you are playing the button prompt inputs might not correspond to the one you have on your physical controller or device you have in your hand.

Xbox Games

The Xbox layout is used by Xbox Controllers.
Is also used by devices like the Steam Deck Rog Alley.
It is used by a lot of Genric third party PC controllers and Xbox Clone Controllers.

Xbox - Button Layout:

Button Placement	Button	Name
North		Y
West		X
East		B
South		A

Example:
So if you are emulating a Xbox game that calls for the button B to be pressed it corresponds to the right button.

Nintendo Games

The Nintendo layout is used by Nintendo Controllers.
It could also be used by other Genric third party Nintendo Clone Controllers.

Nintendo - Button Layout

Button Placement	Button	Name
North		X
West		Y
East		A
South		B

Example:
So if you are emulating a Nintendo game that calls for the button A to be pressed it corresponds to the right button.

Sony PlayStation Games

The Playstation layout is used by Playstation Controllers.
It could also be used by other Genric third party Playstation Clone Controllers.

Playstation - Button Layout

Button Placement	Button	Name
North		Triangle
West		Square
East		Circle
South		Cross

Example:

If you are emulating a PlayStation game that calls for the button Square to be pressed it corresponds to the left button.

Regional differences:

In games from the EU/US Cross is confirm while in Japan Cross is cancel:

Depending on the region of your Playstation game, the buttons Circle and Cross switches the meaning for confirm and cancel (they are still at the same physical location).

But it is good to keep in mind if you are used to exiting out of menus with a certain button and wondering why it works in some games while others not.