The key that deletes text is the backspace key.
When you type, the characters you enter are added to the right of the cursor, which shows you where the next character will be inserted. If you want to delete a character, you can move the cursor to the left of that character using the arrow keys, and then press the backspace key. This will remove the character to the left of the cursor.
You can also use the backspace key to delete a selection of text. To do this, you first need to highlight the text you want to delete by clicking and dragging the cursor over it. Once the text is highlighted, you can press the backspace key to delete it.
In summary, the backspace key is used to delete characters to the left of the cursor or to delete a selected portion of text.