When someone is sectioned it means they are compulsorily admitted to hospital.
the division of the contact line into electrical sections, each of which may be isolated from the adjacent sections e.g. by means of switchestechnique of providing large magnets with several nested coils to decrease internal stresses and voltage across the coil in case of a quench
dividing the hair up into reasonable sections to work within to keep things organized so you dont get lost in hair!
Sectioning your hair allows you to only pay attention to a particular area or panel of hair. You or your hairdresser will do this when blow-drying, cutting or colouring your hair, and will section your hair by taking a panel of hair and pinning or ignoring the rest.