1. The symbol $ is used in mathematics and programming to denote the start and end of inline math expressions in LaTeX formatting. 2. For example, writing $x+1=2$ tells the system to render the expression \(x+1=2\) as a mathematical formula. 3. Outside of math formatting, $ can represent currency in everyday language, but in math and LaTeX, it specifically marks math mode. 4. So, when you see $...$, it means the content inside is a math expression to be formatted accordingly.