Users should note that there are important differences between these data sources, such as comparing census to survey data, differences in how the data are collected and their timeliness.
Dylai defnyddwyr nodi bod gwahaniaethau pwysig rhwng y ffynonellau data hyn, fel cymharu data cyfrifiad i ddata arolwg, gwahaniaethau yn y modd y cesglir y data, a'u hamseroldeb.