What is a built in paragraph style avaiable from the paragraph spacing command that inserts no extra space before or after a paragraph and uses line spacing of 1 is?

The built-in paragraph style you're referring to is typically called "Normal" or "Body Text" in Word processing applications. This style is set to have no extra space before or after paragraphs and uses single line spacing (1.0). It is commonly used for standard text formatting in documents to maintain a clean and uniform appearance.