Links are what connects two ports together. There are two types of Links, normal links and converter links.
To create a Link hold down left mouse button on one of the two Ports drag it all the way to the other and
release left mouse button. Normal Links are in one color which is the color of the data type, converter Links
are in two colors which are the converted data types.
Converter Links are automatically created, when the first Port can be converted to second Port.
You cannot connect two Ports if they both belong to the same Node.
You can only create links between ports that are opposite to each other, which means you can only link IN-OUT or OUT-IN.