Node Techniques
Techniques are the specific methods that nodes use to create features or fulfil a task. Each node has multiple techniques that may have different requirement for completion.
For example, creating a point with the technique ByCartesianCoordinates is much different than creating a point with the technique OnPlane.
Clicking on the Input Port (the downward-facing arrow at the left) expands the list of inputs for current Technique. Unpinned inputs are the required inputs that are the requirements needed to successfully create a node.
Similarly, the Output Port (the downward-facing arrow at the right) expands the list of Common outputs, when unpinned shown on the node.