The key difference lies in their application within the power system. A 33 kV transformer is typically used for medium-to-high voltage power transmission over longer distances to serve large areas or industrial loads. In contrast, an 11 kV transformer is mainly used for local distribution to end-users in residential or smaller commercial zones. 33 kV transformers are generally larger, more expensive, and have a higher capacity to handle greater power loads over a wider area, while 11 kV transformers are more common for lower-demand applications and are often pole-mounted.