A Dowager Queen is the widow of a deceased king; you may also see her referred to as a Queen Dowager, depending on stylistic preference. It is also possible to see a Dowager King, who would be the widow of a queen. As a general rule, this woman is treated in the same way that she was when her husband was alive.
A Dowager Queen's title alerts people to the fact that she was the Queen Consort while her husband was alive, rather than the Queen Regnant. This means that she was given her title by virtue of marriage, rather than inheriting the throne as a birthright. As a general rule, a Queen Consort has no political power, although she is granted the same rank and social status as her husband, and this continues after his death.
It is also possible for a Dowager Queen to be a Queen or King Mother, meaning that she is the mother of the current monarch. In some instances, she has held the throne as regent for a temporary period of time until her children or another suitable heir to the throne has matured to an age where he or she may legally take power. However, a Dowager Queen is not legally permitted to take the throne in her own right, and an attempt to wrest control of the throne from the rightful heir would be viewed as treason.
Although a Dowager Queen may be widowed, she still tends to be an active member of society and of the royal family after an appropriate period of mourning has elapsed. Many continue to support the same issues and causes they supported while acting as Queens Consort, and they often act as notable philanthropists. They are also socially aware individuals, who may take advantage of their reduced ceremonial duties to travel and attend a wide assortment of events.
In some instances, a Dowager Queen becomes a formidable entity, drawing upon years of experience as Queen Consort to provide advice and assistance to her children. She may also be given royal honors on her birthday, and she is given a royal funeral upon her death.