What is the difference between List, Set and Map? Their Usage in salesforce and best practices?

Hi @Hitesh Sharma, If you'd like to learn more about Collections (List, Set, and Map), please refer to the guide and Trailhead module linked below. They provide a clear and practical understanding of these concepts with examples and hands-on exercises. 

https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/langCon_apex_collections.htm

https://trailhead.salesforce.com/content/learn/modules/object-oriented-programming-for-admins/use-sobjects-and-dml