Oxford Dictionary defines ideology is " a set of beliefs, especially one held by a particular group, that influences the way people behave" which means that ideology is set of beliefs and according to these beliefs people think, evaluate and act.
If we had to summarise what ideology is, we could draw inspiration from how we, as humans, think and reason. Human cognition operates under ‘dual processes’ — what psychologists refer to as ‘type 1’ and ‘type 2’ thinking, each type being composed of multiple cognitive systems. The ‘intuitive’ Type 1 is used most of the time — comparable to models of animal cognition, it relies on mental shorthands called ‘heuristics’. This method operates ‘in parallel’, quickly, unconsciously, and using little effort.