Howard Becker's Labelling theory of Deviance is within the umbrella category of Interactionist theory of Deviance. 

Interactionist theories suggest that deviance occurs as part of a process of interactions between deviants and non-deviants. 

Labelling refers to the theory which states that no behaviour or status is inherently deviant until other people have judged it and categorised it as so. 

The theory also questions who has the power and authority to create and attach labels to these groups. 

Interactionists view deviance to be relative as it is an idea and concept created by the people it impacts. 

Becker idenitified two key steps in the process of labelling. These being the labelling of the deviant and the labelling of the behaviour.

Labelling of the deviant: The identifaction of the person or group who are being labelled for their violation of social norms. 

This label can be impacted by various factors including stereotypes, socio-economic status, social status, cultral norms and more. 

Labelling of deviant behaviour: Concerns the specific behaviour that society views as deviant. When the action is labelled it labels the person as the action. Eg. a thief. 

When someone is labelled it influences how people view them is society, it can impact their future opportunities as they may forever be considered by their label, eg a thief.