There are four basic modes of metal transfer

Short Circuit Transfer

Gets its name from the welding wire actually “short circuiting” (touching) the base metal many times per second.  Some spatter is produced, but the transfer can be used in all welding positions and on all thicknesses of metal.

Globular Transfer

Named for “globs” of weld metal transferring across the arc in a gravity feed. Droplets across the arc are usually larger than the electrode diameter.  It does not produce a very smooth weld bead appearance, and some spatter can occur. Usually limited to the flat and horizontal welding positions, and not used on thin metals.

Spray Transfer

Named for a “spray” of tiny molten droplets across the arc, usually smaller than the wire diameter.  Uses relatively high voltage and amperage values, and the arc is “on” at all times after the arc is established.  Very little if any spatter is produced.  Usually used on thicker metals in the flat or horizontal welding positions.

Pulsed-Spray Transfer

For this variation of spray transfer, the welding machine “pulses” the output between high peak currents and low background currents. The weld pool gets to cool slightly during the background cycle, making it slightly different than Spray Transfer. This can allow for welding in all positions on either thin or thick metals.