1.negotiation:a dialogue between two or more people or parties intended to reach a mutually beneficial outcome，resolve points of difference，to gain advantage for an individual or collective，or to craft outcomes to satisfy various interests.Negotiation occurs in business，non-profit organizations，government branches，legal proceedings，among nations and in personal situations such as marriage，divorce，parenting，and everyday life.The study of the subject is called negotiation theory.Professional negotiators are often specialized，such as union negotiators，leverage buyout negotiators，peace negotiators，hostage negotiators，or may work under other titles，such as diplomats，legislators or brokers.谈判，协商

2.interpersonal communication:an exchange of information between two or more people.Communication skills are developed and may be enhanced or improved with increased knowledge and practice.During interpersonal communication there is message sending and message receiving.This can be conducted using both direct and indirect methods.Successful interpersonal communication is when the message senders and the message receivers understand the message.人际沟通，人际交流，人际交往

3.offer:in business，an offer is a proposal to sell or buy a specific product or service under specific conditions.A tender offer is an offer to buy company stock from existing stockholders under specific conditions.An offer price，or ask price，is the price a seller is willing to accept for a particular good.A special offer is a kind of sales promotion.发盘，报盘，要约［当事人一方向对方发出的希望与对方订立合同的意思表示。发出要约的一方称要约人（offeror），接受要约的一方称受要约人（offeree）。］

4.counteroffer:an offer that someone makes，for example，for a house or business，in response to an offer by another person or group；an offer made by someone who has rejected a prior offer还价，还盘，反要约，买方还价

5.BATNA:in negotiation theory，the Best Alternative to a Negotiated Agreement or BATNA is the course of action that will be taken by a party if the current negotiations fail and an agreement cannot be reached.BATNA is the key focus and the driving force behind a successful negotiator.A party should generally not accept a worse resolution than its BATNA.Care should be taken，however，to ensure that deals are accurately valued，taking into account all considerations，such as relationship value，time value of money and the likelihood that the other party will live up to their side of the bargain.These other considerations are often difficult to value，since they are frequently based on uncertain or qualitative considerations，rather than easily measurable and quantifiable factors.达成谈判协议的最佳选择方案；最佳替代方案（常用在采购谈判过程中，采购方为了供需双方的平衡而选择的最佳代替方案。此方案并非采购方最想获得的价格、服务、运输、付款期等条件的最佳方案，而是退而求其次的选择，被设定为谈判的最佳底线。）