This simply means that the voice box has become inflamed. It is frequent following the common cold, as germs move down the upper air passages to become established there. Often the infection remains, giving rise to bronchitis, or even pneumonia if it is not brought under control fairly quickly.
However, there are many other causes. Getting a chill, getting wet and not putting on dry clothes can reduce resistance arid give germs the chance to become established in the larynx. Smoking, alcohol, and even overuse of the voice have been cited as possible causes. In the presence of a mild upper respiratory tract infection, overuse of the voice, shouting and straining can probably help bring on laryngitis. It is common, in this context, in singers and those who use their voices professionally.
Slight hoarseness to a complete loss of ability to make any noise is the range of symptoms. Often there is a sense of constriction around the neck. There may be a huskiness, or total aphonia. Often there will be other symptoms, such as fever, or feeling off-color, or the general symptoms of the underlying infection.