A tender is a submission made by a prospective supplier in response to an invitation to tender issued by an employer. It makes an offer for the supply of goods or services.
There are two purposes in tendering:

To select a suitable contractor at a suitable time. The offer of a price is required from the contractor at an appropriate time. This offer will be the basis for the ensuing contract. Along with the conditions, the contract drawings and bills of quantities (if used) make up the contractual agreements.

There is no direct relationship between the type of tendering procedure and the form of the contractual agreement. The tendering process marks the beginning of the contractual relationship.

Main methods:
1. Open Tendering
2. Selective tendering - single or two stage
3. Nomination / negotiation
4. Serial
5. Joint ventures