Graph the horizontal or vertical line.
\[
y=3
\]
Use the graphing tool to graph the line.

Step 1 ：The given equation is a horizontal line. In a 2D plane, a horizontal line is a straight line that goes from left to right or right to left. The y-coordinate of every point on the line is the same. In this case, the y-coordinate is 3 for all points on the line.

Step 2 ：We can use a graphing tool to graph this line. The x-coordinates can range from -10 to 10, and the y-coordinate for all these points will be 3.

Step 3 ：\(x = [-10, -9.95, ..., 9.95, 10]\)

Step 4 ：\(y = [3, 3, ..., 3, 3]\)

Step 5 ：Plot these points on the graph. Label the x-axis as 'x' and the y-axis as 'y'.

Step 6 ：Final Answer: The graph of the line \(y=3\) is a horizontal line that passes through the point \((0,3)\) on the y-axis. All points on this line have a y-coordinate of 3. \(\boxed{y=3}\)