Kerning is the term used to describe the space between characters in a document. In MS Word, in the Font dialog box, on the 'Advanced' tab, the spacing between characters can be adjusted.
Setting the 'Spacing' to 'Normal' will enter standard spacing between letters. 'Expanded' will increase the spacing between characters, with a higher point size increasing the spacing. 'Condensed' will narrow the spacing with a higher point size bringing the characters closer together.