Particles that Don't Exist

In the complex and often confusing world of physics, there are many confuzzling concepts. One concept I find very confusing, but pretty cool is that thee are particles that exist and don't exist at the same time. These particles are called "virtual particles". Virtual particles are particles that cannot be directly detected since they have zero mass, but the effect of it on a "real" particle can be detected. These particles include photons and gravitons. Most virtual particles can be measured like waves and energy. For example, photons can be represented as a particle or waves/energy (light). Virtual particles are used to explain interactions in physics. For example, an electromagnetic interaction can be described as the exchange of photons.