What are the 4 fundamental forces of nature and what connects them together? How do they interact together?

Gravity is a force that acts on a body's mass property. It is an essentially infinite force, meaning that masses at very great distances will still interact. It is always attractive, with its strength varying inversely as the square of the distance between the masses. As a result, all masses attract all other masses.

(Note: This is not a treatment of general relativity; rather, I am describing gravity as it was understood by Newton.)

Like gravity, electromagnetic force has an infinite range and varies as the inverse square of distance. However, unlike gravity, it acts on charge and can be either repulsive or attractive, meaning that its effects are frequently cancelled out, even for large collections of charge.

According to contemporary theories, this force is referred to as a gauge force, which implies that a particle known as a photon "mediates" the force; in fact, the interaction between the charges is based on the exchange of photons.

You inquire as to how these forces interact, but in actuality, there is no interaction between gravity and electromagnetic; they are two different and distinct forces, though one can be used to reinforce or counteract the effects of the other, just like any other force.

The two nuclear forces are gauge field forces, just like the other one. Their effects are restricted to the atom's nucleus because of their extremely short range.

The nature of the particles that these forces act upon is altered by the exchange of particles; in the case of the strong force, these particles are quarks, and in the case of the weak force, they are quarks and leptons.

The weak force works by using massive particles called W and Z bosons to induce quarks to change their "flavour", which is defined as the "up", "down", "strange", etc. characteristic. For example, it can cause an up quark to become a down quark (or vice versa, depending on which W is involved), which means that a proton changes into a neutron and the affected atom becomes a different element all at the same time.

The strong force acts on the quark's "colour" and is responsible for holding quarks and nucleons together. It is mediated by a particle known as a gluon.

That's probably enough information for now; you should determine whether the above establishes any kind of connection between these forces (the gauge field nature comes to mind, for example).

The four fundamental forces of nature are gravitons for gravity, photons for electromagnetism, W and Z bosons for weak force, and gluons for strong force. These forces interact through particle exchanges, and attempts to unify them through theories such as the Standard Model and Grand Unified Theory have connected them.