We will start by first seeing what kind of particle systems we get in the default package of Unreal Engine 4. Go to Content Browser | Game | Particles. There are a couple of particle systems that we can already drag and place in the level and check out how they look.

To open a particle system, simply double-click on any of the systems. Let's take a look at P_Fire together. Feel free to check out the rest of the systems as well. However, I will use this as an example to understand what we need in order to create a new particle system for our level. This screenshot shows P_Fire in the editor:

On the left-hand side is Viewport where we can preview the particle system. On the right-hand side, in the Emitters tab, you can see several columns of boxes with Flames (twice), Smoke, Embers, and Sparks mentioned on top of each of the columns.

Emitters can be thought of as separate components that make up the particle system, and you can give each emitter different properties depending on what you want to create. When you put a bunch of emitters together, you will see them combining to give you a whole visual effect. In this P_Fire particle system, you can see flames moving in an unpredictable manner with some sparks and embers floating around and smoke simulating a fire bursting into flames. In the next section, let's go through more concrete terminology that describes the particle system in Unreal Engine 4.