Index, Match and populate data

One file, two worksheets. If the serial number on Worksheet1 Column c, row 2 matches a serial number on Worksheet2, Column a, I want the information from worksheet2, column b, same row to be populated in worksheet1, column b, row 2. Then I want to repeat that for all the rows in worksheet1.

Can someone give me a template for this formula? I've been studying Index/Match all morning and just get more confused the more I read. Many thanks!