Often abbreviated to CSRF and often pronounced as “Sea-Surf” is an attack against a Web Application that abuses an application’s trust in the user. An attacker’s aim is to cause a function to execute on the application using the user’s authentication credentials simply by causing the user’s browser to request that function in the normal way, but from a malicious site.
Same-Origin Policy (SOP) is a critical part of the security implemented within a web browser. It’s the part of your browser’s security system that prevents malicious pages from reading confidential information from other sites. So thepiratebay.com can’t read data from barclays.com because it’s blocked by SOP.