What is the difference between Custom Setting and Custom Object in Salesforce?

Custom Object : Custom object is like any Database table that we used to have in SQL or in any other database.

Custom Setting :  Custom Setting is like configuration file that we used to have. List type of custom setting acts like a custom object but there are differences in them like in custom settings there is a limit on no. of records, you can not write trigger, workflow etc on custom setting.

For more information about limits and considerations of custom settings please Check Here.

Hope this answer would be helpful!!

Custom settings are similar to custom objects and enable application developers to create custom sets of data, as well as create and associate custom data for an organization, profile, or specific user. You can use custom settings to store a variety of information that can be accessed easily by other Salesforce tools.

Use and example of Custom Settings
Hard-coding and good code are a match made in hell. RecordTypeIds are most vulnerable to this abuse, and we’re are all familiar with the frustration of finding that code that worked in environment A, suddenly stops working when it is promoted to say test. Why? Because possibly RecordTypeIds are different across the two environments.Why hard-code when you can use Custom Setting.

Custom Settings are a SOQL inexpensive way of storing your configurable parameters in the safe confines of the Salesforce database, with all the conveniences of a custom object – create / edit via point and click – standard salesforce.

Custom Object: Custom objects are custom database tables that allow you to store information unique to your organization.In the API, the names of custom objects include a suffix of two underscores followed by a lowercase “c” . For example, a custom object labeled “Issue” in the Salesforce user interface is Issue__c in that organization’s WSDL.

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