Definition of ideology

I'm reading the culture industry book by Adorno. They talk about a
definition of ideology as a socially necessary appearance. I'm
wondering if they mean that society/culture is set up such that people
need categories and heuristics which then operate to maintain
stability. The particularization of life(style) into types--where
people are socialized to the same cultural schema--actually keeps them
acting relatively uniformly. For example, this act is classified as
deviant, so I won't engage with it, or I will, based on what my
ideology is. If Ideology dictates behavior, controling the definitions
attached to all ideologies means you control the boundaries of
behavior; and also the ability of all people within each division to
see themselves holistically.