How to bisect a line using a compass:
How to subdivide a line into equal spaces
For example, the below video shows how to divide a line into 4 equal spaces
How to proportionally divide a line
Proportionally dividing a line means dividing it according to specific proportions or ratios, which may or may not be equal. For example, you might divide a line into the ratio of 2:3
In this case, you would first divide the line into 5 equal parts, and then split the line at the second point, so that it was in a ratio 2:3.