The UI Input Field provides a space in which the player can enter text.
To create a UI Input Field, select Create | UI | Input Field. By default, the InputField GameObject has two children: a Placeholder and a Text object.
The Placeholder child is a UI Text object that represents the text displayed before the player has input any text. Once the player begins entering text, the Text component on the Placeholder GameObject deactivates, making the text no longer visible. By default, the text displayed by the Placeholder is Enter text…, but the text being displayed as well as its properties are easily changed by affecting the properties on the Text component of the Placeholder.
The Text child is a UI Text object that displays the text the player inputs. Setting the properties on the Text object's Text component will change the display of the text entered...