The document discusses Expectation-Confirmation Theory (ECT) and the Expectation-Confirmation Model (ECM). ECT predicts consumer behavior and marketing strategies based on consumer satisfaction status. It involves consumers forming expectations, experiencing performance, assessing performance against expectations, and forming a satisfaction level. Satisfaction depends on if performance meets, exceeds, or is below expectations. ECM focuses on post-acceptance variables like perceived usefulness and explains user continuance intention based on usefulness, confirmation, and satisfaction. Both theories assess performance against expectations but ECM specifically applies to information systems use.