What are the advantages of Trigger Handler in comparison to the normal trigger operation in Salesforce?

Hi

It is always a best practice to write a single trigger on object and process all operation in apex class (we called it as handler) instead of writing logic in trigger. In handler you can specify the order of event based on different context variables. If you write many triggers in on object,
then you cannot control the order in which triggers gets executed.

For best practice, use below suggestion:

1. Pass all trigger context variables to static method (say “OperationManager”)in handler class.
2. Create different static methods for different operations which you need to perform.
3. Control the order of different operation in “OperationManager” static method based on context variables.
4. Also you can create different apex classes and call them from “OperationManager” static method.

Thanks.

Adding more:

Benefits of the Trigger Handler Pattern
Related reading: Trigger Frameworks and Apex Trigger Best Practices

While my preferred pattern differs slightly, the above article lays out many of the advantages. I personally find a handler implementation must-have because it:

facilitates logic-less triggers and One Trigger Per Object, which itself has many benefits(including fine grained control over order of execution)
improves readability and Separation of Concerns(this improved readability makes version control more fruitful as well)
optionally facilitates selective disablement

Thanks