Checking similarities of the specified columns using distances

I have a 2 excel files which contains string data in excel1 file there is software name and excel2 file there is a product now i have to compare these 2 columns and have to find distance between them like how much percentage those 2 strings are similar and i need to create a new column with name matched and need to write that percentage into newly created column.Can some one help me out how to do this with distances.

EXCEL - 1:

EXCEL - 2: