HOW TO MATCH TWO OR MORE SETS OF STRINGS

Hi. I want to compare two strings in two different columns. For example, 

Cell A1 = where can i find an apple store 

Cell A2 = i found an apple store

I want excel to match the two cell values and highlight the different words (including number, if there's any) in Cell A2. 

Example, Cell A2 = i found an apple store

Hope someone can help me. Thanks.