招标，是一种市场交易、搜索商业对象的行为。 招标指在一定范围内公开货物、工程或服务、采购的条件和要求，并邀请众多投标人参加投标，之后按照原先规定进程，从中选择合适者作为交易对象。

依招标种类

• 竞争性招标
  • 公开招标
  • 选择性招标（邀请招标）
• 议标，又称为「谈判招
• 两阶段招标，先「公开招标」，再「选择性招标」

依决标方式

• 最有利标
• 最低标

A call for bids, call for tenders, or invitation to tender (ITT, often called tender for short) is a special procedure for generating competing offers from different bidders looking to obtain an award of business activity in works, supply, or service contracts. They are usually preceded by a pre-qualification questionnaire (PQQ).