There are two types of polarity in Direct Current. Among these two polarities: one is Direct Current Electrode Negative (DCEN) and another one is Direct Current Electrode Positive (DCEP).
The electrode Negative (-) is the TIG Torch is connected with the negative end of the circuit or terminals and on the other hand, the electrode Positive (+) is the TIG Torch is connected with the positive end of the circuit or terminals.
Direct Current flows the electricity in only one direction and that flows from the negative (-) terminal to the positive terminal (+).