What is the design term for a straight line on a page or screen?

The design term for a straight line on a page or screen is commonly referred to as a "rule" or "line." In graphic design, rules are used to separate or organize content, direct the viewer's eye, create emphasis, or provide a visual aesthetic to the layout. These lines can be horizontal, vertical, or diagonal and can vary in thickness, style, and color depending on the design's purpose and the message the designer wants to convey. In digital design, such as web design, these lines are often created using CSS (Cascading Style Sheets) or within graphic design software like Adobe Illustrator or Photoshop.