The section tool will give you a live section (always updates unless you set it to manual) and the elements will still be the original 3D elements.
You can manipulate the heights and widths of a section so you can achieve the same view as a detail.
The detail tool will give you a fixed view converting all 3D elements into 2D lines and fills.
You have to manually update a detail if your model changes.
So it just depends what you want.
One of the forum moderators. Versions 6.5 to 25 Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10 Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10