How to compare & then sum/list differences between spreadsheets?

[Pheasant Plucker®]

I have a spreadsheet that is updated & sent to me weekly.

Up until now I have been comparing the two sheets side by side and cutting &
pasting the differences into a new spreadsheet to summarize/list the
differences.

Now the spreadsheet is becoming larger and taking more time I am guessing
there is a way to quickly compare the two sheets & sum the differences?

Can some kind soul please explain to an Excel idiot how to achieve this
please? ;^)

 

[Guest]

Take a look here for some ideas:

http://www.cpearson.com/excel/duplicat.htm#CountingUnique

(there are other "aids" on Chip's site)

Are the differences always additions only or can items be removed.

And what data needs to be compared and summated