The theoretical framework of this thesis provides a structured lens through which to analyze the complex dynamics of fact-checking and misinformation in digital media. It integrates multiple perspectives, including innovation diffusion, strategic business considerations, gatekeeping and framing theories, psychological concepts, and trust models, to comprehensively understand how fact-checking methods are adopted, implemented, and received across platforms and audiences. This framework guides the research design and analysis by linking platform strategies, user behaviors, and broader socio-political contexts, enabling a nuanced exploration of the challenges and opportunities in combating misinformation online.