1. Positive Charge: Represented by the symbol '+'.

2. Negative Charge: Represented by the symbol '-'.

These charges interact with each other in the following ways:

* Like charges repel: Positive charges repel other positive charges, and negative charges repel other negative charges.

* Opposite charges attract: Positive charges attract negative charges.

The concept of a "third" type of charge is not part of our current understanding of electromagnetism.