How to conditionally check if value in Excel Sheet is the same as one another and if true return value of other field in another sheet?

I've got some Excel Workbook which for purpose of this will have two Sheets in it.

1. Main Sheet where I've got a Person and Company
2. Here I have company but need to conditionally get output like:

if company in 2nd Sheet is the same as in Main then get the Person from main and put it in the column in 2nd Sheet

for example:
Main Sheet has following data: Alina and Company is Dellthen what I want is to check whether I have Dell in Company column in 2nd sheet and if yes then automatically fill in the name(Alina) in that column.