A site consists of one master feature class (attribute) with related line, point and polygon feature classes. Each network point can be connected to a site.
Sites are not part of the network topology. They are a useful means to group various features of the utility network to make them reachable. A site stores for example house number and location.
The easiest way to connect a network point to a site is to use the Network Point Creation workflow.
Use the Site Creation workflow to create sites that by default are related to one geometry feature. However, you can add more geometries and equipment features using the feature class form.