Many times when we paste contents from other documents or programs to Word, the formatting in the open document is lost and the contents copied from other sources will have the default formatting. So after pasting contents from other sources or document, we have to format it again and this becomes a tedious job many times. You can set Word to take the formatting of the current document while pasting contents from other sources.
To set this option, click the Office button on the top left corner and select word Options.
Select the Advanced tab in the Word options and scroll down to cup, Copy and Paste section.
Here you can select which formatting to use by default when copy/pasting contents from other documents or programs. You can also enable the Smart Cut and paste which automatically matches the formatting of the destination document.