The document summarizes and compares two theories - Media Dependency Theory from 1976 and Social Cognitive Theory from 2002 - and evaluates their relevance to social media today. Media Dependency Theory proposes that individuals rely on media to fulfill three needs: understanding their social world, acting meaningfully in that world, and fantasy or escape from problems. It identifies three forms of dependency on media. Social Cognitive Theory explains how environmental, behavioral, and cognitive factors interact to influence individuals' behavior. The document analyzes how concepts from both theories apply to modern social media behaviors and features.