Adding to what Graham has said:

• What happens when I send my document to someone else? Will Word mess up my formatting?
• Why has my page layout changed when I open my document on a different machine? by Suzanne Barnhill, MVP
• What is the relationship between a Microsoft Word document and its template?

That may be more information than you need.

Point on Word jargon: These days, it is the normal.dotm template, not the normal.dot template. There are times when that is important.