A market consists of all the potential customers sharing a particular need or want who might be willing and able to engage in exchange to satisfy that need or want.
Marketer and Prospect
When one party is more actively seeking an exchange than the other party, we call the first party a marketer and the second party a prospect. A marketer is some one seeking one or more prospects who might engage in an exchange of values. A prospect is someone whom the marketer identifies as potentially wiling and able to engage in an exchange of values.
Philip Kotler (Marketing Management, 9th Edition)