20 SFDC interview questions

(If these questions are useful please let me know,then i will post some more real time interview questions)

1.What is the many to many relationship,how you create it?

2.What is the difference between trigger.new and trigger.old?

3.How to restrict any trigger to fire only once?

4.What is the difference between Workflows and Triggers?

5.What are the differences between SOQL and SOSL?

6.What are the sharing rules ,how you provide sharing rules?

7.Can you use DML statements in SOSL and SOQL?

8.What is Customization ,what are the Custom Settings?

9.How you delete class from Production Environment?

10.If you have 1 million records how can u upload them?

11.What are the Action Commands?

12.Explain render ,rerender, renderas?

13.Explain about Collections?

14.Explain about validation rules and how you used validation rules in your project? 

15.How can you invoke Apex class?

16.Explain about code coverage?

17.How can you restrict an user to access particular  record?

18.How can we send an email to particular person in SFDC?

19.Differences between profile and role?

20.Differences between profiles and permission sets?