Contact Poi vs Normal Poi

The standard poi are the most common, by far. They are most suitable for beginners looking to start spinning and learning the basics.
Contact poi are more suited to experienced spinners looking to advance their skills and learn even more technical tricks. The contact poi are much heavier and hit harder. The ropes are thicker too, which is great for throws, allowing the handle and the ball end to remain stable in the air. The rope is not only thicker but also stiffer. It's common to use static rope climbing cord for contact poi.

As a rule of thumb, if you are just starting out, standard poi may be the best option for you.
If you are looking for more room to explore ideas and moves, the contact poi do open up more options.

Both are good and you can start with either type, but this is the general guide.