Here are few terms that I use often:
USP: Unique selling proposition; what sets a brand/product/service apart from everybody else.
ROI: Return on investment; what you aim for in your marketing expenditure.
Brand equity: The value (in dollars and in positive associations) for a brand.
Brand personality: How a brand is perceived.
CPM: Cost per thousand
Target market: Who you are trying to reach. Defined by demographics (age, income, gender, location) and psychographics (lifestyle, personality, preferences).