Network Marketing--Is marketing to people in your network. Your network includes friends, family, coworkers, and people you meet on a daily basis. Sometimes it is intentional marketing and other times it is discussing the latest book you read, television show or movie you watched, or song you listened to and by recommending it to someone you are marketing it to them whether you mean to or not.
Network Marketing as a Business--You market a specific product or service to your network.
Direct Selling--A form of network marketing where you are an independent distributor for a company and market their products/services to customers. The customers buy the products through you and you earn commission.
Warm Market--People you already know that you are close to already. Friends, Family, and Coworkers.
Cold Market--People you do not know personally; People You Meet are cold market until they can be considered part of your warm market.