“The acid-induced reaction that converts oxime to amide is called Beckmann rearrangement” 

In the Beckmann rearrangement, migration of the group does not depend upon migration aptitude but depends upon the orientation of the group related to a hydroxyl group. In the case of Beckmann rearrangement, that group will always migrate which is anti to the hydroxide group (OH). German Chemist Ernest Atto Beckmann gave this rearrangement.

Oxime:

Oximes contain C=N-OH groups derived from aldehyde and ketones by condensing them with hydroxylamine.

Types of Oximes:

Oximes are of two types

Aldoxime:

It is a combination of aldehyde with hydroxylamine.

Ketoxime:

It is the combination of ketones with hydroxylamine.