I assume you are referring to oceanic currents (instead of electrical current).
Oceanic current is divided into 2 types:
Surface Ocean Current -- affected by wind.
Deep Ocean Current --cause by water density (mineral rich vs clearer water) and temperature gradient (differences in heat)
When the flow of current is aways in one direction it is known as direct current.
The direction of current due to flow of electrons is opposite to the direction of conventional current. This is because electrons have a negative charge, so when they flow in a wire, they are actually moving in the opposite direction to the current flow defined by convention.
direction of magnetic field
A negative answer in a Kirchhoff's Current Law calculation indicates that the assumed direction of current flow was incorrect. It suggests that the actual direction of current flow is opposite to the assumed direction. Therefore, the sign of the calculated current should be corrected to reflect the actual flow direction.
A current consisting of charges that flow only in one direction is called direct current (DC). In DC, electrons flow continuously in one direction from the negative to the positive terminal of a power source.
Direct current (DC) does not reverse its direction of flow. This means that the flow of electrical charge in a DC circuit always moves in one direction, from the positive terminal to the negative terminal.
Current Density describe how charge flow at certain point since current density = I/A and the vector direction tells you about the direction of flow at that point.
The name for the potential difference that causes current to flow is voltage.
The polarity of an electromagnet can be determined by the right-hand rule. If the direction of the current flow is known, curl your right hand fingers in the direction of the current flow. Your thumb points in the direction of the north pole of the electromagnet.
DC current
In a DC circuit, the direction of current flow is from the positive terminal of the voltage source to the negative terminal.
on a three way switch.alternating current.