The major difference between a tuner-style wheel nut and a standard wheel nut is the diameter size. Tuner nuts have a smaller diameter (typically 20mm or 23mm), they are for wheels that are specifically designed to use the smaller diameter nuts. They also require a special key to install and remove the nut.
What is the need for tuner nuts?
When you purchase alloy wheels they will typically have either 4 or 5 bolt holes to match your vehicle. There are also wheels called multi-fitment, which allows for the wheel to be used on vehicles with different PCDs. Multi-fitment wheels can come with up to 10 holes.
For the multi-fitment wheels to have up to 10 holes they need to be a smaller diameter to fit them on the wheel. This a where tuner nuts are needed. Standard wheel nuts cannot be used on these wheels as they physically will not fit in the wheel holes.