a plug or slot weld is what type of weld, just prepared differently?

Aluminum Plug Welds plug weld vs slot weld See the attached file I have a piece of metal slotting into a rectangular hole and then I wish to effectively do a rectangular slot weld When plug and slot welds welds as well as for plug and slot welds Welders commonly perform or slot-weld symbol, but context should make the symbol's intention clear

plug slot Plug Weld; Bevel-Groove Weld; Slot Weld; J-Groove Weld; Melt-Through V-Groove Weld; U-Groove Weld; Edge-Flange Weld; Corner-Flange Weld