Why MS Word changes character spacing in a document?

Apparently, MS Word changes character spacing for individual words at its will. I would like to ask:

1. Why does this happen?
2. Is there any benefits in this?
3. In my opinion, it has no benefits. It even harms the document by cluttering some words as far as I observed. So how can I force the Word to keep a constant character spacing?

2 Answers

Usually this happens when you use the "justified" attribute on a paragraph. Change it to right, left or center alignment and it should fix this.

You can adjust character spacing in the Advanced tab of the Font dialog. Highlight some text, right click on the selection, and click Font.

For a description (and screenshots) of the various spacing options, read the Microsoft Word: Font - Advanced page help article.