Conjoint analysis is a market research technique used to understand customers' preferences for different product features. It involves assessing customers' ratings, rankings, or choices between hypothetical products defined by various attribute levels to estimate the value or "part-worth" that customers place on each attribute level. This helps companies design products with optimal combinations of features to satisfy customers. The method originated in psychology in the 1970s and uses computer surveys to consider many attributes and levels simultaneously, simulating real purchase decisions involving trade-offs between features.