Customer expectations are beliefs about the level of service that will be provided. There are two types of expectations: desired service, which is the optimal level hoped for, and adequate service, which is the minimum tolerable level. Factors like personal needs, past experiences, available alternatives, and situational factors influence expectations. Gaps can occur when customer expectations do not align with a provider's understanding of them, service design, delivery of service, or communications about the service. Measuring perceptions against expectations on reliability, responsiveness, assurance, empathy, and tangibles can identify service quality issues using the SERVQUAL model. Addressing gaps within the organization is important to improve customer satisfaction.