What is Apex Trigger in Salesforce?

Apex triggers in Salesforce are pieces of code that execute before or after specific data manipulation language (DML) events occur. These events can include insertions, updates, deletions, or merges on Salesforce objects. Triggers are essential in customizing and extending the functionality of Salesforce by automating tasks and enforcing data quality.

When a DML event occurs, the trigger is invoked, allowing developers to write custom logic in Apex to perform actions like validation, calculations, or updates on records. Triggers play a crucial role in maintaining data integrity and implementing complex business processes within Salesforce applications.

Key points about Apex triggers in Salesforce:

1. Trigger Execution:

Triggers can be executed either before the records are inserted, updated, deleted, or merged (Before Triggers) or after the operation has been completed (After Triggers).

2. Context Variables:

Triggers have access to specific context variables like Trigger.new (new records), Trigger.old (old records), Trigger.newMap (new records in a map), and Trigger.oldMap (old records in a map) to help developers analyze and manipulate the data.

3. Bulk Processing:

Triggers are bulk-enabled, meaning they can handle operations on multiple records simultaneously. Developers should write trigger logic