The first stage of the purchase decision process begins with "problem recognition" (also known as category need or need arousal). This is when the consumer identifies a need, typically defined as the difference between the consumer's current state and their desired or ideal state. A simpler way of thinking about problem recognition is that it is where the consumer decides that he or she is 'in the market' for a product or service to satisfy some need or want. The strength of the underlying need drives the entire decision process.