This report provides a detailed analysis of consumer behaviour and insight (CBI), focusing on the consumer decision-making journey and its various stages. It explores how marketers map the path to purchase, emphasizing the importance of understanding consumer decision-making. The report examines different decision-making models, such as utility theory, satisfying, and prospect theory, and evaluates how marketers respond to these processes through strategies like compensatory and non-compensatory approaches. It also contrasts the key differences in the decision-making process between B2C and B2B contexts, providing specific examples. Furthermore, it evaluates various market research approaches and methods used to understand decision-making in both B2C and B2B environments, including environmental studies, qualitative research, and online surveys. Finally, the report analyzes the different factors, including economic, functional, marketing mix, personal, psychological, social, and cultural factors, that influence consumer decision-making and buying behaviour, supported by relevant examples, such as the purchase of a Huawei mobile phone.