Transactional analysis proposes that people operate within three ego states - parent, adult, and child - and that interactions between these states can be categorized into nine possible transactions. Healthy relationships involve complementary transactions where one person's response appropriately continues the discussion. Crossed transactions, where the response does not fit the initial stimulus, often cause difficulties and are characteristic of games people play in interactions. The initiator of a transaction provides a stimulus, and the respondent's reaction is the transactional response which then becomes the new stimulus for the next response.