How to check which Salesforce edition we are using | Which salesforce edition

What edition of Salesforce do you have?

Solution :- We can check the same from below two option

1) Browser :- Click on Tab then you can see the detail like below screen shot

2) By Company Setup :- Best Option is to check the same from company profile.
Setup- > Company profile 
like below screen shot. 

Thanks,
Amit Chaudhary