Ranula is -
Ranula 

Ranula, also known as mucous retention cyst, is a type of muscle found on the floor of mouth on one side of the frenulum.
It arises from sublingual salivary gland, due to obstruction of its duct and is almost always unilateral.
It occurs mostly in children and young adults.

Clinical features

A ranula is usually asymptomatic, and only complain is fluctuant swelling with a bluish translucent colour.
Swelling is painless unless it becomes secondarily infected.
Overlying mucosa is intact and ranula is not fixed.

Treatment

Surgical excision of both the gland as well as the lesion. Ranulas are likely to recur if the sublingual gland causing them is not removed with the lesion.
Hypertrophied lymphoid tissue
Arises from mucosa of floor of mouth
Hard and Hemorrhagic
An abscess