vlookup type function, see if string has key, if it does give value

So i need to do a vlookup type function, where i need to search for a key in an array, if i find it, spit out the value.

For the array i'm using a table on sheet 2.

On sheet one Col A is the string I want to search, col B is where I would want the category to show.

Sheet two has col A with the Key (Merchants) and I want to show the Category which is Col B