The pins allow electrical connection to the symbol. Use the menu command Edit=>Add Pin/Port to add a new pin.
The "Pin Label Position" determines how the pin label is presented. "TOP", "BOTTOM", "LEFT", and "RIGHT" are text justifications. For example, if a pin label is TOP justified, the pin(the label's text justification's anchor point) will be above the label. If the symbol represents a SPICE primitive element or a subcircuit from a library, then the pin label has no direct electrical impact on the circuit. However, if the symbol represents lower-level schematic of a hierarchical schematic, then the pin name is significant as the name of a net in the lower level schematic.
The "Netlist Order" determines the order this pin is netlisted for SPICE.