Definition - What does Same Origin Policy (SOP) mean?
Same origin policy (SOP) is a security mechanism in a client browser that permits webpage scripts to access their associated website’s data and methods but restricts its access to scripts and data stored by other websites.
Techopedia explains Same Origin Policy (SOP)
Same origin policy is a common feature found in most client scripting languages and their created applications that relyon HTTP cached cookies for user authentication, access control and other security related tasks. Same origin policy is designed to ensure that separate website scripts and applications do not interfere with the access control credentials of other websites.
The origin in this policy relates to the evaluation of top level domain name, application protocol, port number, and some browser specific considerations. It is generally applicable to all the websites, scripts, applications services, etc that require the browser to maintain user sessions.