One of the most frequently posed Flutter developer interview questions, be ready for it.   If we are using a column, then MainAxis is y i.e., it aligns the widgets vertically with respect to the value of “MainAxis”, the value can be start, center or end and if we are using a row, then MainAxis is X i.e., it aligns the widgets horizontally with respect to the value of “MainAxis,” the value here also can be start, center, or end.