The Euclidean distance between points p and q is the length of the line segment that connects them. For two points (p(x_1, y_1)) and (q(x_2, y_2)), the Euclidean distance (d) is calculated as:

[ d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} ]

This formula represents the straight-line distance in a two-dimensional space. In MATLAB, you can compute this distance using the following code snippet:

p = [x1, y1];
q = [x2, y2];
d = sqrt(sum((p - q).^2));
d

For more details, you can refer to the Wikipedia page.