What are Remote Site Settings in Salesforce

Salesforce allows you to access external website resources from a Salesforce application for your organization. You can access these external websites through Visualforce pages, Apex Callout, and via XmlHttpRequest calls. To avoid accessing malicious websites from Salesforce.com, the website first needs to be registered with remote site settings. Once the site is registered, it can be used within Salesforce.com. 

To Setup the Remote Site Setting 

• search and click remote site settings in setup.
• Click on New Remote Site and enter the URL and other fields required.
• Click Save.

Please find the description of the fields in remote site settings

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