Hi Subbu, A Qualifier allows a field to maintain different type of data.For example ,if 'date' is a field with quilifier ,then that date field can hold a) creation date b)sold date c)delivery date etc....
Why Does My Mucus Change Color? If you've ever stopped to look at the contents of the tissue after you've blown your nose, you may have noticed that your mucus isn't always perfectly clear. It may be yellow, green, or have a reddish or brownish tinge to it. What do those colors mean? You might have heard that yellow or green mucus is a clear sign that you have an infection, but despite that common misperception, the yellow or green hue isn't due to bacteria. When you have a cold, your immune system sends white blood cells called neutrophils rushing to the area.
Green Mucus. Green mucus can appear at the beginning or the end of an illness. Usually, however, a toddler will have clear mucus at the beginning of the illness, then develop yellow or green mucus as the condition progresses. Your toddler is at her most contagious state when her mucus is clear, according to the California Childcare Health Program. As she begins to get over the cold, her mucus may turn green or yellow as she excretes large numbers of white blood cells that died fighting the illness.