Answer:
Sutures are a device to hold a wound together or to close a surgery. the easiest way to think about it is to sew your body together. the device looks like thread with a curved needle (usually 3/8 circle) on the end.
In human body the skull bones are united together by type of joints which are also known as Sutures. they do not provide any mobility and thus a for ma protective case around Brain, the Cranium
They are immovable joints that hold skull bones together.