This symbol is regularly used to denote XOR in logic. When using the usual two-valued logic, and using the symbol + for OR, ' for NOT, and * (or just concatenation) for AND, then

  • X ⊕ Y = (XY') + (X'Y)

This symbol then represents the familiar either-or concept: either X or Y, but not both. The AND/OR form reads X and not Y or not X and Y.