I’m Unable to Link Excel Sheet with MS Word.

I'm working with MS Word & Excel files and I've prepared an Excel Sheet, which I want to integrate/link with my Word file. I copied the cells from the Excel sheet & then pasted special into Word file.
The data was copied into the Word file, but the copied data is not updated into Word file, when I change it into the Excel sheet. Please tell me, what is the correct method of linking an Excel sheet into MS Word file.
