It is called the header at the top of the page and a footer at the bottom of the page
That is called the margin, good sir.
The space between an object and text is often referred to as padding or margin. Padding is the space inside the border of the object, while margin is the space outside the border of the object. Adjusting padding and margin can help control the layout and spacing of elements on a page.
Margin
The space between the text and the top edges of the paper is known as the margin. It provides a clear boundary for the text and ensures that the content is well-organized and visually appealing. Margins also allow room for binding or hole-punching documents.
In retail, a front margin, sometimes referred to as a gross margin, is the difference between the invoice price and the final retail price, or Gross Sales - Cost of Goods Sold. A back margin is other income for a business that comes in later on a monthly basis.
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It depends on the context. in writing, a margin is a space around the main body of text, which is usually blank. A margin in business is the difference between the cost of producing an item and the amount it's sold for.
you can either use margin-left: 10px; padding-left: 10px; or text-indent: 10px; however text-indent will only indent the first line of text, for differences between padding and margin lookup css box-model
In typesetting the space between lines is called lead or leading. The space between letters is keening.
Footer
The page margin - is the limits to the left & right that text will be printed. A paragraph indent is a margin (left and right) further from the edges of the page - usually used to emphasise a piece of text.
For a paragraph, to have both sides having a straight margin, the text is said to be justified. Some extra space can be used to push the text towards the margins.