Consider the following plot with 3 lines added:
The line labeled 9sc3dSCnWwKkktSY is the least-squares line.
The least-squares line minimizes the squared residuals in the G4NkLPXJX2goMOYtUYU+RzGf8KMwqm51f+gPcOPGFaOTSAgkR8eOpA== direction from the line to the points.