1. Let's understand what Cartesian coordinates are. They represent a point in a plane using two numbers: the $x$-coordinate (horizontal position) and the $y$-coordinate (vertical position). 2. The coordinates are written as an ordered pair: $(x, y)$. 3. For example, the point $(3, 4)$ means move 3 units right along the $x$-axis and 4 units up along the $y$-axis. 4. The origin is the point $(0, 0)$ where the $x$-axis and $y$-axis intersect. 5. To plot a point, start at the origin, move horizontally by the $x$ value, then vertically by the $y$ value. 6. Cartesian coordinates are fundamental in algebra, geometry, and physics to describe locations and graph functions.