I think tsl summed it right on the button. When I started out and saw where I needed some lights, I got some minor ones. The more I rode in the wee dark hours of the morning and evening, along with city and rural road traffic, better lighting was not a choice, I had to get something different and better. Now, with better lighting, I see a VAST improvement in the way the other vehicles see me. I see them jump back, when they were getting ready to take my right-of-way, and stop when they see me coming. I contribute all that to my lights. The choice of the type and kind of lights is up to the rider. For myself, I am running double flashlight torches up front, helmet light, in rear, strong blinky on the bike, one on my helmet, and sometime one or two on my leg. Up front, I am burning.

I am running blinky mode in the daytime.
I started with some of those lights that are being suggested, and I quickly saw where I was way undergunned.

Luck and safe commuting to you.